(student) interview questions - programming for a robotics lab - c++

my robotics lab is looking for programmers to work on some projects we have at the moment.
We nailed down the requirements (mainly, c++ and experience with openGL and 3D), but due to obvious money constraints we can't afford to hire Great Developers. Instead we're going to settle for Talented Students, offering them projects for their dissertation/thesis and hoping for some fresh ideas and creativity from their side. We can also afford to pay students that just graduated (first job experience).
So my question is:
In your experience, how did you spot a Talented Student (computer scientist or engineer)? What questions did you ask? What else did help you in finding a candidate that turned out to be a Good Programmer? (note: they might not know much about a specific language, but might have the ability to learn pretty fast)
or, if you were the interviewee,
Which questions were asked that made you jump on the bandwagon? Or, if you had an awful experience, what - in retrospect - was an obvious warning signal that you ignored?
Please note that I am not looking for an argumentative answer. We can talk all day long about what's best for us and never agree.
Instead, I'm looking for tales from your experience. Anecdotes, stories, hints, everything will help.
Background:
A bit more background: working for academia here is slightly different than working for the private sector (here = Italy). There are no 'deadlines' to 'sell' a product; instead, it's all proof-of-concept based. Nothing you start working on has the guarantee to be functional.
A comic best describes it: reinventing the wheel
I am considering doing Coding Questions for their interview, but all my colleagues are scoffing at me (too scary, nobody will ever come to work for us again, nobody really know how to code, etc).
Coding-wise, programming done by researchers is ... ugly. I am fighting to get a version control system in constant use, people have to be chased down to report bugs and document their code, everything is coded-so-that-it-works and rarely we go back to old code to 'fix bugs'. Basically once it's somewhat working, the project is closed and people go work on another project.
Lots has been reinvented and rewritten over and over again (just because nobody knew it was already there). People come and go, future is uncertain, but we play with robots so it's very cool :)
Furthermore, being really understaffed, nobody can follow you and guide you in your project. At best you're the one that has to come up with a plan, background literature and a working prototype.
Hence, we are looking for people that:
have some background to get started
can be highly independent
do want to learn and build their own expertise in new fields

Actually, here's my best advice:
Recruit among your students.
Since you work for an academic institution I assume that either you or your colleagues teach. This provides you with a wealth of information about what potential recruits are capable of -- how fast they learn, how motivated they are, what they are good and bad at, how the code they turn in for the lab assignments and projects look like, etc.

Firstly, in industry, coding questions are very much the norm - I'd be worried if coding questions weren't asked!
I've been responsible for doing technical interviews for about ten years now. And yes, I ask coding questions. But the questions themselves aren't really the point. What I'm more interested in is getting an idea of whether the candidate can think, and articulate their thoughts.
One question I ask (asuming the simple earlier stuff has gone well) is about inheritance heirachies. There is no one right answer, although there are a lot of wrong ones. But what's important is how they approach the question, the points they come up with in favour of one design over another.
Background knowledge is useful, in that it shows that they have an interest in the area in which you're working - but really knowledge can be gained. Intelligence is much more important.
However it's quite possible to have intelligent people who are impossible to work with! I haven't figured out how to determine who they are.

I have done such a project when I was a student: ie a 4-months project, working half-time. It was not about robots, per se.
I think that the most obvious requirement is motivation/passion. Since they'll be mostly on their own you will need them to be somewhat independent and able to think for themselves, this requires motivation first and foremost.
In order to determine whether the candidate is motivated or not, begin by asking them about the project itself. If they only gave it a cursory glance, they're likely not motivated. Also look at their experience / courses: optional courses in CS, projects they've done, etc... anything indicating that they really care about CS / development in general and are not there just because they've heard it paid well.
Then comes the question of ability. Like you said it might not be easy to spot those who will be smart enough to figure stuff out by themselves and DO things. Once again, you can ask them about past projects, having them detail the issues they faced and how they solved it.
Finally, I agree with you that some demonstration of their abilities is in order. They might be a bit tense initially, so I would do this at the end, once the interview is already going, you might have had a chance to get them to relax with the previous questions this way.
You don't necessarily need them to do coding questions, I think it's most about reasoning. Try to pick problems related to your area work, for example one you really had in the past, and get them to analyze the problem. If possible they should take the lead and ask you questions about the problem itself here.
We've had an issue with the robot not being able to analyze the images the camera took, it could not correctly determine the moving objects itself, do you have an idea how you would do that ?
Then you'll need to get them to think about a solution. You need a whiteboard here, and ask them to think aloud so that you can follow their reflexion. You'll probably need to nudge them a bit from time to time to keep them on track, their reaction to your input is also a key-point here, since you want them to be able to accept criticism and build on it, otherwise you might have issues directing them afterward.
Frankly, try to avoid asking them for the quicksort algorithm, or the introsort, or the radix sort... If they need sorting, they'll just fire up their computer and browse the internet. On the other hand, getting them to analyze an existing algorithm unknown to them (for example, the median of 5 sort) and checking that they understand why it works, could be worth it. If they need to work on their own, they'll need to be able to learn on their own too :)

As others say, try to hire someone that's motivated!
For master thesis students I put more emphasis on knowing the basic skills (programming, knowing how to use version control) as they don't stay on long enough to learn everything along the way.
If they're going to work mostly on their own and you have no special requirements on language I wouldn't focus much on language questions. But every decent programmer knows at least one language fairly well, get a sample or their prior work or make them code some simple application to test that they don't suck.
I'd focus more on algorithm and data structures. Ask rudimentary stuff that every programmer should know - when to use a list and when to use a vector, why summing a row-major matrix by iterating over the columns first is bad, basic complexity analysis questions, etc. That will sort out many of the bad weeds.
Ask some design questions too perhaps, e.g. what is "coupling" and why is it bad, ask them if they know what a design pattern is, etc.
Check that the applicants have a solid grasp of linear algebra and coordinate system changes in particular if they're going to work with any 3D stuff like OpenGL. In my experience, learning the API is simple, wrapping your head around how the transformations work less so.
Obviously, if you except them to perform any real robotics-specific you should check for that knowledge as well. E.g. estimation (understanding simple EKF and particle filters is a requirement in my book), control theory, pattern recognition, machine learning, vision, or whatever is useful for the particular task.
If I were hiring someone for theoretical work I would perhaps loosen up on the CS/programming skills and focus more on math knowledge. Someone with solid math skills will pick up the CS easily, and programming is just programming.
Ask for references or to see some of the prior work. Many great students already have some interesting project to show after graduation.

I'm not sure how common this is at universities in general, but I would look for a games programming (or robotics) course on the transcript where the candidate, as a student, succeeded in completing a project with a team. It would ask the candidate to describe how that project worked (important technical details) and the role he had in the team. The only way to really tell if someone is good at something is to see what happens when they try it, and since you're in academia, recruiting students, that should not be a problem.

Related

How do you understand a large chunk of code?

I am a fresh college grad student that just started my job. In my ramp up period, I need to learn a lot of product code. There are some design docs but they do not help much.
Can you provide some general techniques to browse and understand huge product code (specifically C++)?
Run it through doxygen. This will generate html documentation which will be helpful even if the code does not have proper doxygen-style comments.
Another good advice is to look through the unit tests, if there are any. If there are no unit tests, a good way to understand the code is to write your own unit tests. The effort to do this will pay for itself many times over.
Use every method available to you (in no particular priority):
Use the product itself and understand what it does
Talk to the devs that maintained it or have worked with it previously
Debug through it and see how data flows and how classes interact ("when I click this button, what exactly happens, who is responsible?")
Look at architecture, UML, or class diagrams
One of my favorites: create your own diagrams of class hierarchies, class interactions, general control flow, high-level components, process/DLL interactions, object lifetimes and management
If they're not totally out-of-date, read the dev/test/user specs (goes well with #1)
Read the documentation on it
Most of all: be tenacious and persistent. If you don't put in the work, don't expect to understand it. If you don't understand something, dig and dig until you do. Software is not magic, it's just hard work :)
Some people will tell you to start with the data structures, but in a large system even that's not terribly helpful much of the time. I can think of four major points:
Take your time. Often, it's more like a whole series of gestalt shifts than it is a single, linear, gradual understanding. So be patient.
No matter how big it is, you should be able to put a breakpoint in and walk it in a debugger. Even in a large, complicated, multi-threaded system, you should be able walk through and see what's happening.
Ask for bugs, and start fixing them, no matter how crazy they seem. It's akin to dropping yourself into a foreign country; you'll pickup the language eventually.
Find a mentor. A jungle guide is invaluable.
I think there have been a few good responses already. My 2c worth...
Not sure what you class as huge (10 KLOC, 1000 KLOC, 10000 KLOC, etc), but one would hope that this is broken down in some way and is not a monolithic single program. Perhaps your management has some guidance on which 'module(s)' you are most likely to be spending time in at the moment. Hopefully this can help break down the problem scope.
Firstly, before you try to understand the code try to understand the product. What does it do? Then how does it do it? What does it interact with? Then how does it interact? etc...
When getting to the code try to understand the high level design and philosophy first, and work on the breadth before the depth. I agree with some of the above re fixing some bugs, but I also strongly suggest you continue to get a handle on the high level even if you need to get into the details to fix some bugs.
I also agree with the above in terms of generating some diagrams for yourself if you can't find any already in existence. And then share them, perhaps a team/product wiki? I'm curious as to why the existing doco does not help very much. Typically this is because this type of doco was generated from the early concepts and the product no longer bears any similarity, but if this is not the case then what can you contribute to this issue. One assumes that where you are today someone else will be in short enough order, and you are in an ideal position to know what essential doco is missing!
If the product is actually 'huge' then you have to accept that you will never be able to hold all of it in your head, so the best thing you can do is be familiar enough to know where to start looking (comes back to understanding the product, and approaching code breadth first).
This is obviously a pretty common question, and it's similar to this one (and the questions related to it): How to understand the design and code flow of any product quickly?
Dig through some of those answers / comments, for starters. Else, we'll just end up repeating them. :)

How to deal with seniors' bad coding style/practices? [closed]

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I am new to work but the company I work in hires a lot of non-comp-science people who are smart enough to get the work done (complex) but lack the style and practices that should help other people read their code.
For example they adopt C++ but still use C-like 3 page functions which drives new folks nuts when they try to read that. Also we feel very risky changing it as it's never easy to be sure we are not breaking something.
Now, I am involved in the project with these guys and I can't change the entire code base myself or design so that code looks good, what can I do in this situation?
PS> we actually have 3 page functions & because we do not have a concept of design, all we can do is assume what they might have thought as there is no way to know why is it designed the way it is.
I am not complaining.I am asking for suggestion,already reading some books to solve the issues Pragmatic Programmer; Design portion from B.Stroustrup; Programming and principles by B.Stroustrup;
The best and most important thing you can do is lead by example. Do things the right way and try to improve things slowly. You aren't going to fix anything overnight.
Make sure every piece of code that you are responsible for is better after you are done with it. Over time, the system will tangibly be better because of your efforts.
After you build a strong reputation with your co-workers, try go start some code reviews or lunch-training sessions to get everyone up to speed on better ways to do things.
In a nutshell: it will be difficult and frustrating, but it's possible. Good luck.
Your best bet is to NOT to handle it at all. Here are potential problems if you try:
You will be criticized for doing something you were not told to (makes performance reviews go real bad.)
You will have less time to do your own work.
You will not advance your career by cleaning working code- if it is not broke then do not touch it.
Never make enemies with people who control your career- unintentionally implying they are obsolete morons does not help your cause (especially in a bad economy).
Focus on making your own code great. Battling poorly written code is part of the ill of being a Software Engineer. You are in the wrong profession if you will not stand for it.
A little off point but important- You may need to switch jobs or teams if possible once the economy picks up. Mixing with a truckload of bad coders who do not bother to update their knowledge and practices dulls your own programming skills and weakens your marketability.
If you're a junior dev, then the only thing you can really do is write code as elegantly and readable as possible.
If your style is indeed better, other people might notice and say "hey we should adopt this formula"
Actions speak louder than complaints, which is something I noticed.
The present is embodied in Hexagram 47 - K'un (Oppression): Despite exhaustion, there may yet be progress and success. For the firm and correct, the really great man, there will be good fortune. He will fall into no error. If he make speeches, his words cannot be made good.
The future is embodied in Hexagram 6 - Sung (Conflict): Though there is sincerity in one's contention, he will yet meet with opposition and obstruction. If he cherish an apprehensive caution, there will be good fortune. If he prosecute the contention to the bitter end, there will be evil. It will be advantageous to see the great man. It will not be advantageous to cross the great stream.
I was in the exact same shoes before. I got hired as a C++ programmer to 'lead the team' on how to use C++ by an enthusiastic manager. That was about a decade ago. Some of the newer engineers loved me, the seniors despised me. Our system was basically a pseudo-C++ system. It was like C with classes, but it appeared that people didn't even understand the usefulness of things like constructors since they hardly appeared.
You complain about functions that are 3 pages long; we had functions that were 8000 lines long full of long jumps, function pointer casts, etc. One of the seniors even formatted the code with 2-space indentations so that super deep nested blocks can be written without using much horizontal space since the seniors seemed to be allergic to writing functions and procedural programming in general. Someone even inlined a 2000 line function thinking it would make things faster. You might be dealing with some bad code, but I was dealing with the most horrid copy-and-paste code imaginable.
Unfortunately I was very young and cocky. I didn't get along with the seniors, I fought against them in territorial battles over code. They responded by creating coding standards which no sane C++ programmer could follow (ex: it's okay to use operator new, but don't use exception handling, don't use constructors or destructors, etc). As a result I wrote the most bizarre and stupid standards-workaround C++ code just to kind of rebel against those standards since I refused to write C-style code given the reason I was hired (I didn't hate C so much, but writing C code was not part of the job description: I was hired essentially as a C++ consultant), even though the standards made C-style coding the only practical way to do things. I only kept my job because I put in so much overtime to make sure that my code works very well in spite of these ridiculous coding standards.
It wasn't until years later when others started to see things my way that we lifted the silly standards and started writing more natural, easy-to-read C++ code complete with STL and boost goodies, RAII, exception-handling, etc. That isolated the seniors who refused to write code in a more sane fashion and they were finally forced to adapt.
In retrospect, I could have done things much better. The seniors were intent not to allow me to be put in a teaching position, but I think I would have gotten my point across much faster with my head down. The biggest regret I have is trying to work around the impossible coding standards rebelliously rather than getting them rectified through clear and rational discussions. As a result, I have really stupid and obfuscated C++ code in the system which people attribute to me even though that's not how I normally write C++ code. The regular developers I work with understand this, but the seniors still point to it as an example of why C++ is bad.
In short, I recommend that you focus on making more friends rather than enemies. Your friends will support you, and if your way is better and you can clearly demonstrate it, you can isolate the few who will never agree.
Being enthusiastic to code the right way is a good trait to possess and in the software industry we will always encounter other developers who write code that is not quite in line with our "perfect way" of coding. This should never be interpreted as rubbish code, or inept coders, because we all start out like that in some shape or form.
Always respect your peers around you as you want them to respect you. It's certainly not easy to do in an environment that highly regards ego, but attempting to approach a topic like this is never easy.
It's how you communicate
Try different approach angles, remember you are there to learn as much as to render a service.
So commenting on the "poor" code style in an "in-your-face" kind of approach might not be the result you were looking for. So then back up a bit and try approaching the topic with "I was considering the style of code used and have a few suggestions..." and see the difference that gives.
Where I work now, the one thing I've learnt is that it's fine to comment on something that's might not be good quality but then I had better have a better solution to present.
In other words, be prepared to back up your words with useful solutions and not because you feel so.
This is the most basic reason why establishing coding standards and code review processes are a good idea.
I will not write three page functions no matter what coding standards and processes are established, but some people will. They will create 20 local variables at the beginning, without initializing any of them. You'll have pointers and integers with unspecified values. You won't know the exact meaning and scope of each variable. Etc etc.
Try to convince your manager and, later, your team, with solid arguments. Maybe you could start with a shared reading of Effective C++ or C++ Coding Standards. Try to stress the point that, when working this way and creating better code, everybody wins. If they see this as a win-win situation, they will be more open to the change.
I can empathize.
I'm below two senior programmers who have very unique styles that I find frustrating. We have code that consists of one main function that's 1000 lines long. (That is not a typo.) Our coding standards discourage globals, so we make every program one App object. Now our globals are member variables! When we need an iteration interface for C++ classes, why should we use the begin, end, and operator++ conventions, when First, AtLast, and Next can be used instead. We've wrapped up third party libraries in custom interfaces for no good reason. (We've wrapped log4cxx and lost functionality for no reason I can tell, and one of our date classes consists of a shared pointer to a boost::date object with a fraction of the functionality.)
Here's how I've kept my sanity. I've focused on the new languages and tools. This is our company's first project involving Python, and I've spent my time writing utilities and programs there. While the senior programmers code in what they're familiar with, I've got near free rein of all the Python code. I couldn't stand the C++ APIs we use, so I duplicated most of the same functionality in Python in a much more friendly way, and the other developers prefer it too.
Likewise, we have little familiarity with log4cxx and less with boost-build, both of which I've taken time to study in depth and know good enough that people come to me with questions. I've written a handful of resources on our wiki giving usage tips for log4cxx and numpy and other tools.
This is how it is, get used to it or quit and find a place where it isn't like that. You will be marginalized if you criticize their efforts and they may feel threatened if you do indeed write your own, better code or improve theirs. At the end of the day they deliver code and management sees a black box that works and that's all that matters. Plus, you'll be just another kid from college who thinks he knows something about development at a business and laughed at and ostracized when not around. Honestly, a lot of the times these systems are built like this because of shaky requirements, lots of functionality bolted on with time and managements lack of respect for a stable software development process.
Not all companies are like this. I'd start looking for a new job to be honest.
I fervently hope, this is the best opportunity to grow by facing the challenge.As Robert said,try to lead by example.If possible let them adopt your pattern.
You are not alone. I too faced recently, luckily we have support from Senior Management for Code Reviews.
1. Even a single line change for Bug fix should be reviewed online.
Comments on code can be classified as CodingStandard/Suggestion/Clarification/Major/Minor etc
While giving comments to senior you can start with Clarification/CodingStandard rather than Major
You could address the issue of "we are afraid to touch it for fear of breaking it" by writing extensive unit tests. Once you get the unit tests in place, you will be freed to refactor at will. If your unit tests still pass after the refactoring, you can be confident you haven't broken anything.
Just place a copy of "Clean Code" (Martin), "Refactoring: Improving the Design of Existing Code" (Fowler) or "Effective C++" somewhere in the office where people may start browsing the books. From now on, word will spread. Seriously, its never too late to learn! ;)

How to read code without any struggle

I am a new to professional development. I mean I have only 5 months of professional development experience. Before that I have studied it by myself or at university. So I was looking over questions and found here a question about code quality. And I got a question related to it myself. How do I increase my code understanding/reading skills? Also will it improve the code quality I will write? Is there better code notation than Hungarian one? And is there any really good books for C++ design patterns(or the language doesn't matter?)?
Thank you in advance answering these questions and helping me improving :)
P.S. - Also I have forgot to tell you that I am developing with C++ and C# languages.
There is only way I've found to get better at reading other peoples code and that is read other peoples code, when you find a method or language construct you don't understand look it up and play with it until you understand what is going on.
Hungarian notation is terrible, very few people use it today, it's more of an in-joke among programmers.
In fact the name hungarian notation is a joke itself as:
"The term Hungarian notation is
memorable for many people because the
strings of unpronounceable consonants
vaguely resemble the consonant-rich
orthography of some Eastern European
languages."
From How To Write Unmaintainable Code
"Hungarian Notation is the tactical
nuclear weapon of source code
obfuscation techniques; use it! Due to
the sheer volume of source code
contaminated by this idiom nothing can
kill a maintenance engineer faster
than a well planned Hungarian Notation
attack."
And the ever popular linus has a few words to say on the matter.
"Encoding the type of a function into
the name (so-called Hungarian
notation) is brain damaged—the
compiler knows the types anyway and
can check those, and it only confuses
the programmer."
- Linus Torvalds
EDIT:
Taken from a comment by Tobias Langner.
"For the differences between Apss Hungarian and Systems Hungarian see Joel on Software".
Joel on Software has tips on how to read other people code called Reading Code is Like Reading the Talmud.
How do I increase my code
understanding/reading skills?
Read read read. Learn from your mistakes. Review answers on SO and elsewhere. When you can think back on a piece of code you wrote and go "aha! I should've done xyz instead!" then you're learning. Read a good book for your language of choice, get beyond the basics and understand more advanced concepts.
Then, apart from reading: write write write! Coding is like math: you won't fully grock it without actually solving problems. Glancing at a math problem's solution is different than getting out a blank piece of paper and solving it yourself.
If you can, do some pair programming too to see how others code and bounce ideas around.
Also will it improve the code quality
I will write?
See above. As you progress you should get more efficient. It won't happen by reading a book on design patterns. It will happen by solving real world problems and understanding why what you read works.
Is there better code notation than
Hungarian one?
It depends. Generally I avoid them and use descriptive names. The one exception where I might use Hungarian type of notations is for UI elements such as Windows Forms or ASP.NET controls, for example: using btn as a prefix for a Submit button (btnSubmit), txt for a TextBox (txtFirstName), and so on but it differs from project to project depending on approach and patterns utilized.
With regards to UI elements, some people like to keep things alphabetical and may append the control type at the end, so the previous examples become submitButton and firstNameTextBox, respectively. In Windows Forms many people name forms as frmMain, which is Hungarian, while others prefer naming it based on the application name or form purpose, such as MainForm, ReportForm, etc.
EDIT: be sure to check out the difference between Apps Hungarian and Systems Hungarian as mentioned by #Tobias Langner in a comment to an earlier response.
Pascal Case is generally used for method names, classes, and properties, where the first letter of each word is capitalized. For local variables Camel Case is typically used, where the first letter of the first word is lowercase and subsequent words have their first letters capitalized.
You can check out the naming conventions and more from the .NET Framework Design Guidelines. There is a book and some of it is on MSDN.
And is there any really good books for
C++ design patterns(or the language
doesn't matter?)?
Design patterns should be applicable to any language. Once you understand the concept and the reasoning behind that pattern's usefulness you should be able to apply it in your language of choice. Of course, don't approach everything with a "written in stone" attitude; the pattern is the goal, the implementation might differ slightly between languages depending on language features available to you. Take the Decorator pattern for example, and see how C# extension methods allow it to be implemented differently than without it.
Design Pattern books:
Head First Design Patterns - good beginner intro using Java but code is available for C++ and C# as a download (see "book code and downloads" section on the book's site)
Design Patterns: Elements of Reusable Object-Oriented Software - classic gang of four (GOF)
Patterns of Enterprise Application Architecture - Martin Fowler
If you're looking for best practices for quality coding in C++ and C# then look for the "Effective C++" and "More Effective C++" books (by Scott Meyers) and "Effective C#" and "More Effective C#" books (by Bill Wagner). They won't hold your hand along the way though, so you should have an understanding of the language in general. There are other books in the "Effective" series so make sure you see what's available for your languages.
I'm sure you can do a search here for other recommended reading so I'll stop here.
EDIT: added more details under the Hungarian Notation question.
I can't speak for everyone else, but in my experience I've found that the best thing I learned about making readable and/or in general better code was reading (and ultimately cleaning) a lot of other people's code. Some people may disagree with me but I think it's invaluable. Here's my reasoning:
When you start programming, its difficult to determine what is crap vs. not crap vs. good. Being logical, rational and extremely intelligent help in making good code, but even those factors don't always contribute. By reading others works and doing the dirty work, you'll have gone through the experience of what works and what doesn't. Eventually, you'll be able to mentally navigate those minefields that others had to cross and you'll be prepared to avoid those identical minefields.
By reading other's works, you gain insight into their mind and how they tackle a problem. Just from an architecture or technique aspect, this can be very useful to you whether their
tactics were good or bad. By reading other peoples successful or unsuccessful implementation, you've gained that knowledge without putting in the actual time it took them to learn it.
Design patterns are extremely useful. Only time and experience with them will help you in knowing what the appropriate pattern for whichever problem. Again, read other peoples' code for this if they've successfully built some pattern that may be useful for you.
When dealing with extreme problems where people's work falls short, you learn to research and dive into the internals of whatever system/language/platform/framework you're working with. This research ability on your own is very useful when all else fails. But you'll never know when to start looking or for what until you get through the crud of other people's work. Good code or bad, it's all valuable in some form or fashion.
All these notations and formats and nomenclature are helpful, but can be learned or implemented rather quickly and their payoff is fairly substantial. By reading code from other people, you'll develop your own style of logic. As you encounter other peoples work and the tremendous amount of effort it takes to read through, you'll learn what logical pitfalls to avoid and what to implement the next time for yourself or even how to fix bad code even faster.
I've never felt as if I was a great programmer. Not to say I'm a bad one either, but I feel confident in my abilities as my experience has taught me so much and my ability to adapt to every situation is what makes me a solid programmer. Learning from other people and their code has helped me. Whether their work was good or bad, there's always something you can take from them and their experience, add it to your memories, knowledge, etc.etc.
Ask other people to read your code! Try and see if you get a fellow coworker or similar to have a code review with you. Having someone else comb through your code and ask you questions about your code will provide new insights and critiques to your style and techniques. Learn from your mistakes and others.
Just to give you a bit of encouragement, I've been a professional programmer for 30 years now, and I still find reading other people's code very difficult. The major reason for this, unfortunately, is that the quality of the code follows Sturgeons Law - 90% of it is crap. So don't think it's your fault if you find it hard going!
The biggest improvement in readability of my code came about when I started liberally using white space.
I found this article on Joel on Software to be very relevant to the Hungarian notation debate.
It seems that the original intent of the notation was to encode type information that wasn't immediately obvious- not whether a variable is an int (iFoo), but what kind of int it is- such as a distance in centimeters (cmFoo). That way, if you see "cmFoo = mBar" you can tell that it's wrong because even though both are ints, one is meters and the other is centimeters, and thus the logic of the statement is incorrect, even though the syntax is fine. (Of course, I personally prefer to use classes such that that statement wouldn't even compile, or would do the conversion for you).
The problem was at some point people started using it without understanding it, and the world was cursed with lots of dwFoos and bBars.
Everyone needs to read that article- Making Wrong Code Look Wrong
How do I increase my code
understanding/reading skills?
Reading code is like dancing by yourself. You need a partner, and I suggest a debugger.
Stepping through code with a debugger is a true, lively dance. I recommend getting a quality, open-source project in the language of your choice, and then step through with the debugger. Concepts will come alive if you ask "why did that happen?", "what should happen next?".
One should ultimately be able to reason about code without a debugger; don't let it become a crutch. But that said, it is a very valuable tool.
Reading code is a lot like reading literature in that you need to have some insight into the author sometimes to understand what you're looking at and what to expect. They only way to improve your comprehension skills is by reading as much code and possible and trying to follow along.
I think a lot of what is mentioned here is applicable to coding...
Reading and understanding skills are a question of time. You will improve them as you get more experienced. Also depends in the quality of the code you are reading.
Keep in mind that sometimes it's not the best idea to learn directly from what you see at work. Books will teach you the best practices and you will be able to adapt them to yourself with the experience.
I am reading the Head First Design Patterns at present and it is very useful. It presents the information in a novel way that is easy to understand. Nice to see they have a C# version for download.
There will always be struggles with reading code unless you are Jon Skeet. This isn't to say that it is a big problem, rather that unless you can eat, sleep, breathe in that programming language, it will always take a little time to digest code. Looking at other people's code is certainly a good suggestion for helping in some ways but remember that there are many different coding conventions out there and some may be more enforced than others, e.g. interface names start with an I to give a simple example. So, I guess I'm saying that even with Visual Studio and Resharper, there is still a little work to understand a few lines of code since I can't quite write out sentences in C# yet.
1) Educate yourself. Read relevant literature.
2) Write code
3) Read code
4) Read relevant blogs.
Visit http://hanselminutes.com . He is a programmer from microsoft. Even though you don't program on microsoft stack, it's good to read through. There is a podcast in there that answers this question.
Another suggestion is to make sure you have the appropriate tools for the job before you start digging into a piece of code. Trying to understand a code-base without the ability to search across the entire set of files is extremely difficult.
Granted, we very rarely have the entire set of files, especially in large projects, but whatever boundaries you draw, you should have good visibility and searchability across those files. Whatever lies outside those boundaries can be considered 'black box' and perhaps lies outside the scope of your grokking.
There are many good open source editors including Eclipse and the CDT. Spending some time learning how to effectively create projects, search across projects, and enable any IDE-specific tooltips/helpers can make a world of difference.

Where to get peer review of code and how to get my code attention?

I'm just now learning to programming at age 17. It's hard for me to talk to other programmers as I'm just out of high school (which means I can't take programming courses). I know that I write terrible code, and not like Jeff Atwood terrible code, my code actually sucks. So where can I post some of my code and get real programmers to review it. I know if I had a question I could ask it on StackOverflow, but I want to post a whole class and get a review on it.
The real problem here is that I'm not going to be writing the next great piece of Software. I'm going to be writing a really useless class, which will serve no other purpose than to teach me how to program. This code will never be used, ever! EVER! How can I get an advanced (or even intermediate) programmer to look at my code?
Thanks in advance! ;-)
Look to the open source community. There are plenty of existing and new projects that would love an eager (if inexperienced) developer to offer support.
Going this route offers two advantages:
You get to see great code in action and learn from it
Any changes you submit will be reviewed by an experienced developer and they will often give you excellent suggestions as to how to improve your code before it will be accepted
Start by choosing a project in your language (there are a bunch in c++) and check out the code. You don't need to understand it all, but you must be able to understand at least a portion of it.
If the project looks way to complicated, keep looking. Younger projects tend to have less code that you need to learn.
If you can't get great programmers to look at your code, do the next best thing: look at theirs!
Look for a bunch of code snippets that do the same (simple) thing. Before you look at them too closely, write your own code to perform the same task. Compare all of the snippets with your own (and each other!) and try to figure out the reasons for the differences.
I recommend looking for code from well established projects. Code from tutorials often ignores important details for the sake of simplicity.
Why don't you try RefactorMyCode?
I would try not to write useless code, but attempt to solve some particular problem. Your learning will be more advanced if you are learning in the context of a real-world scenario. It doesn't have to be a big business domain; could even be a game or a shareware utility.
As for getting your code reviewed, the open source community is a good way to go as The Lame Duck says - in fact you're guaranteed it gets some form of review if you actually contribute to a project. Other avenues to explore: your local C++ users' group, checking out a co-op program available through a junior college, or engaging someone in a company that sponsors interns.
I haven't tried sites such as RefactorMyCode as suggested by Gilad Naor, but that seems promising. And, yes, StackOverflow is a good place for bite-sized chunks of code. If you do that, explain what you are trying to do, and why you are trying to do it that way, and ask if there's a better approach. Good luck!
I think the best way to learn is the way I learned (I may be biased): trial and error. I just wrote programs all the time, teaching myself as I went. I'd write terrible code, and I would wrestle with making it do what I wanted. Often it would make me give up on that particular project. But on the next project, I'd take a different approach, and it would work better. Repeat ad nauseam. Once you know where the rough spots are in your designs, you'll be able to ask specific questions on places like SO, or, better yet IMHO, come up with better designs yourself. I independently invented all the major design patterns just through frustration at the solutions I'd created in the past. I think this gives me a valuable perspective, since for most people design patterns are just a "best practice", but I know the pain that comes with using other designs, and I can see signs of bad designs in code very easily (it takes one to know one). This last skill is one that I often see lacking in other programmers... they can't see why their design is deficient and they should use something else.
You could always try a site like Project Euler, where there are a whole load of problems that will test your skills and a whole bunch of solutions to those problems, submitted by others. Project Euler tends to focus on algorithms rather than higher level programming constructs, but I imagine that there are others in a similar vein.
Do something fun and don't worry too much about code style yet. I started out with BASIC on Commodore 64 without even realizing that there was such a thing as clean code vs dirty code. If I had worried a lot about that then, it might have hindered me from progressing. You always learn best when doing it playfully.
Maybe a bit late, but since StackExchange has Code Review, it worth the answer:
Code Review Stack Exchange is a question and answer site for peer
programmer code reviews. It's 100% free, no registration required.
Here is the link: Code Review Stack Exchange

How to make junior programmers write tests? [closed]

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We have a junior programmer that simply doesn't write enough tests.
I have to nag him every two hours, "have you written tests?"
We've tried:
Showing that the design becomes simpler
Showing it prevents defects
Making it an ego thing saying only bad programmers don't
This weekend 2 team members had to come to work because his code had a NULL reference and he didn't test it
My work requires top quality stable code, and usually everyone 'gets it' and there's no need to push tests through. We know we can make him write tests, but we all know the useful tests are those written when you're into it.
Do you know of more motivations?
This is one of the hardest things to do. Getting your people to get it.
Sometimes one of the best ways to help junior level programmers 'get it' and learn the right techniques from the seniors is to do a bit of pair programming.
Try this: on an upcoming project, pair the junior guy up with yourself or another senior programmer. They should work together, taking turns "driving" (being the one typing at they keyboard) and "coaching" (looking over the shoulder of the driver and pointing out suggestions, mistakes, etc as they go). It may seem like a waste of resources, but you will find:
That these guys together can produce code plenty fast and of higher quality.
If your junior guy learns enough to "get it" with a senior guy directing him along the right path (eg. "Ok, now before we continue, lets write at test for this function.") It will be well worth the resources you commit to it.
Maybe also have someone in your group give the Unit Testing 101 presentation by Kate Rhodes, I think its a great way to get people excited about testing, if delivered well.
Another thing you can do is have your Jr. Devs practice the Bowling Game Kata which will help them learn Test Driven Development. It is in java, but could easily be adapted to any language.
Have a code review before every commit (even if it's a 1 minute "I've changed this variable name"), and as part of the code review, review any unit tests.
Don't sign off on the commit until the tests are in place.
(Also - If his work wasn't tested - why was it in a production build in the first place? If it's not tested, don't let it in, then you won't have to work weekends)
For myself, I have started insisting that every bug I find and fix be expressed as a test:
"Hmmm, that's not right..."
Find possible problem
Write a test, show that the code fails
Fix the problem
Show that the new code passes
Loop if the original problem persists
I try to do this even while banging stuff out, and I get done in about the same time, only with a partial test suite already in place.
(I don't live in a commercial programming environment, and am often the only coder working a particular project.)
Imagine I am a mock programmer, named... Marco. Imagine I have graduated school not that long ago, and never really had to write tests. Imagine I work in a company that doesn't really enforce or asks for this. OK? good! Now imagine, that the company is switching to using tests, and they are trying to get me inline with this. I will give somewhat snarky reaction to items mentioned so far, as if I didn't do any research on this.
Let's get this started with the creator:
Showing that the design becomes simpler.
How can writing more, make things simpler. I would now have to keep tabs on getting more cases, and etc. This makes it more complicated if you ask me. Give me solid details.
Showing it prevents defects.
I know that. This is why they are called tests. My code is good, and I checked it for issues, so I don't see where those tests would help.
Making it an ego thing saying only bad programmers don't.
Ohh, so you think I am a bad programmer just because I don't do as much used testing. I'm insulted and positively annoyed at you. I would rather have assistance and support than sayings.
#Justin Standard: On start of new propect pair the junior guy up with yourself or another senior programmer.
Ohh, this is so important that resources will be spent making sure I see how things are done, and have some assist me on how things are done. This is helpful, and I might just start doing it more.
#Justin Standard: Read Unit Testing 101 presentation by Kate Rhodes.
Ahh, that was an interesting presentation, and it made me think about testing. It hammered some points in that I should consider, and it might have swayed my views a bit.
I would love to see more compelling articles, and other tools to assist me in getting in line with thinking this is the right way to do things.
#Dominic Cooney: Spend some time and share testing techniques.
Ahh, this helps me understand what is expected of me as far as techniques, and it puts more items in my bag of knowledge, that I might use again.
#Dominic Cooney: Answer questions, examples and books.
Having a point person (people) to answer question is helpful, it might make me more likely to try. Good examples are great, and it gives me something to aim for, and something to look for reference. Books that are relevant to this directly are great reference.
#Adam Hayle: Surprise Review.
Say what, you sprung something that I am completely unprepared for. I feel uncomfortable with this, but will do my best. I will now be scared and mildly apprehensive of this coming up again, thank you. However, the scare tactic might have worked, but it does have a cost. However, if nothing else works, this might just be the push that is needed.
#Rytmis: Items are only considered done when they have test cases.
Ohh, interesting. I see I really do have to do this now, otherwise I'm not completing anything. This makes sense.
#jmorris: Get Rid / Sacrifice.
glares, glares, glares - There is a chance I might learn, and with support, and assistance, I can become a very important and functional part of the teams. This is one of my handicaps now, but it won't be for long. However, if I just don't get it, I understand that I will go. I think I will get it.
In the end, the support of my team with play a large part in all this. Having a person take their time to assist, and get me started into good habits is always welcome. Then, afterward having a good support net would be great. It would always be appreciated to have someone come a few times afterward, and go over some code, to see how everything is flowing, not in a review per se, but more as a friendly visit.
Reasoning, Preparing, Teaching, Follow up, Support.
I've noticed that a lot of programmers see the value of testing on a rational level. If you've heard things like "yeah, I know I should test this but I really need to get this done quickly" then you know what I mean. However, on an emotional level they feel that they get something done only when they're writing the real code.
The goal, then, should be to somehow get them to understand that testing is in fact the only way to measure when something is "done", and thus give them the intrinsic motivation to write tests.
I'm afraid that's a lot harder than it should be, though. You'll hear a lot of excuses along the lines of "I'm in a real hurry, I'll rewrite/refactor this later and then add the tests" -- and of course, the followup never happens because, surprisingly, they're just as busy the next week.
Here's what I would do:
First time out... "we're going to do this project jointly. I'm going to write the tests and you're going to write the code. Pay attention to how I write the tests, coz that's how we do things around here and that's what I'll expect of you."
Following that... "You're done? Great! First let's look at the tests that are driving your development. Oh, no tests? Let me know when that is done and we'll reschedule looking at your code. If you're needing help to formulate the tests let me know and I'll help you."
He's already doing this. Really. He just doesn't write it down. Not convinced? Watch him go through the standard development cycle:
Write a piece of code
Compile it
Run to see what it does
Write the next piece of code
Step #3 is the test. He already does testing, he just does it manually. Ask him this question: "How do you know tomorrow that the code from today still works?" He will answer: "It's such a little amount of code!"
Ask: "How about next week?"
When he hasn't got an answer, ask: "How would you like your program to tell you when a change breaks something that worked yesterday?"
That's what automatic unit testing is all about.
As a junior programmer, I'm still trying to get into the habit of writing tests. Obviously it's not easy to pick up new habits, but thinking about what would make this work for me, I have to +1 the comments about code reviews and coaching/pair programming.
It may also be worth emphasising the long-term purpose of testing: ensuring that what worked yesterday is still working today, and next week, and next month. I only say that because in skimming the answers I didn't see that mentioned.
In doing code reviews (if you decide to do that), make sure your young dev knows it's not about putting him down, it's about making the code better. Because that way his confidence is less likely to get damaged. And that's important. On the other hand, so is knowing how little you know.
Of course, I don't really know anything. But I hope the words have been useful.
Edit: [Justin Standard]
Don't put yourself down, what you have to say is pretty much right on.
On your point about code reviews: what you will find is that not only will the junior dev learn in the process, but so will the reviewers. Everyone in a code review learns if you make it a collaborative process.
Frankly, if you are having to put that much effort into getting him to do something then you may have to come to terms with the thought that he may just not be a good fit for the team, and may need to go. Now, this doesn't necessarily mean firing him... it may mean finding someplace else in the company his skills are more suited. But if there is no place else...you know what to do.
I'm assuming he is also a fairly new hire (< 1 year) and probably recently out of school...in which case he may not be accustomed to how things work in a corporate setting. Things like that most of us could get away with in college.
If this is the case, one thing I've found works is to have a sort of "surprise new hire review." It doesn't matter if you've never done it before...he won't know that. Just sit him down and tell him your are going to go over his performance and show him some real numbers...take your normal review sheet (you do have a formal review process right?) and change the heading if you want so it looks official and show him where he stands. If you show him in a very formal setting that not doing tests is adversely affecting his performance rating as opposed to just "nagging" him about it, he will hopefully get the point. You've got to show him that his actions will actually affect him be it pay wise or otherwise.
I know, you may want to stay away from doing this because it's not official... but I think you are within reason to do it and it's probably going to be a whole lot cheaper than having to fire him and recruit someone new.
As a junior programmer myself, I thought that Id reveal what it was like when I found myself in a similar situation to your junior developer.
When I first came out of uni, I found that it had severly un equipped me to deal with the real world. Yes I knew some JAVA basics and some philosophy (don't ask) but that was about it. When I first got my job it was a little daunting to say the least. Let me tell you I was probably one of the biggest cowboys around, I would hack together a little bug fix / algorithm with no comments / testing / documentation and ship it out the door.
I was lucky enough to be under the supervision of a kind and very patient senior programmer. Luckily for me, he decided to sit down with me and spend 1-2 weeks going through my very hacked togethor code. He would explain where I'd gone wrong, the finer points of c and pointers (boy did that confuse me!). We managed to write a pretty decent class/module in about a week. All I can say is that if the senior dev hadn't invested the time to help me along the right path, I probably wouldn't have lasted very long.
Happily, 2 years down the line, I would hope that some of my collegues might even consider me an average programmer.
Take home points
Most Universities are very bad at preparing students for the real world
Paired programming really helped me. Thats not to say that it will help everyone but it worked for me.
Assign them to projects that don't require "top quality stable code" if that's your concern and let the jr. developer fail. Have them be the one to 'come in on the weekend' to fix their bugs. Have lunch a lot and talk about software development practices (not lectures, but discussions). In time they will acquire and develop the best practices to do the tasks they are assigned.
Who knows, they might even come up with something better than the techniques your team currently uses.
If the junior programmer, or anyone, doesn't see the value in testing, then it will be hard to get them to do it...period.
I would have made the junior programmer sacrifice their weekend to fix the bug. His actions (or lack there of) are not affecting him directly. Also, make it apparent, that he will not see advancement and/or pay increases if he doesn't improve his skills in testing.
In the end, even with all your help, encouragement, mentoring, he might not be a fit for your team, so let him go and look for someone who does get it.
I second RodeoClown's comment about code reviewing every commit. Once he's done it a fair few times he'll get in the habit of testing stuff.
I don't know if you need to block commits like that though.
At my workplace everyone has free commit to everything, and all SVN commit messages (with diffs) are emailed to the team.
Note: you really want the thunderbird colored-diffs addon if you plan on doing this.
My boss or myself (the 2 'senior' coders) will end up reading over the commits, and if there's any stuff like "you forgot to add unit tests" we just flick an email or go and chat to the person, explaining why they needed unit tests or whatever. Everyone else is encouraged to read the commits too, as it's a great way of seeing what's going on, but the junior devs don't comment so much.
You can help encourage people to get into the habit of this by periodically saying things like "Hey, bob, did you see that commit I did this morning, I found this neat trick where you can do blah blah whatever, read the commit and see how it works!"
NB: We have 2 'senior' devs and 3 junior ones. This may not scale, or you might need to adjust the process a bit with more developers.
It's his Mentor's responsibility to Teach him/her. How well are you teaching him/her HOW to test. Are you pair programming with him? The Junior more than likely doesn't know HOW to set up a good test for xyz.
As a Junior freshout of school he knows many Concepts. Some technique. Some experience. But in the end, all a Junior is POTENTIAL. Almost every feature they work on, there will be something new that they have never done before. Sure the Junior may have done a simple State pattern for a project in class, opening and shutting "doors", but never a real world application of the patterns.
He/she will only be as good as how well you teach. If they were able to "Just get it" do you think they would have taken a Junior position in the first place?
In my experience Juniors are hired and given almost same responsibility as Seniors, but are just paid less and then ignored when they start to falter. Forgive me if i seem bitter, it's 'cause i am.
Make code coverage part of the reviews.
Make "write a test that exposes the bug" a prerequisite to fixing a bug.
Require a certain level of coverage before code can be checked in.
Find a good book on test-driven development and use it to show how test-first can speed development.
Lots of psychology and helpful "mentoring" techniques but, in all honestly, this just boils down to "write tests if you want to still have a job, tomorrow."
You can couch it in whatever terms you think are appropriate, harsh or soft, it doesn't matter. But the fact is, programmers are not paid to just throw together code & check it in -- they're paid to carefully put together code, then put together tests, then test their code, THEN check the whole thing in. (At least that's what it sounds like, from your description.)
Hence, if someone is going to refuse to do their job, explain to them that they can stay home, tomorrow, and you'll hire someone who WILL do the job.
Again, you can do all this gently, if you think that's necessary, but a lot of people just need a big hard slap of Life In The Real World, and you'd be doing them a favor by giving it to them.
Good luck.
Change his job description for a while to solely be writing tests and maintaining tests. I've heard that many companies do this for fresh new inexperienced people for a while when they start.
Additionally, issue a challenge while he's in that role: Write tests that will a) fail on current code a) fulfill the requirements of the software. Hopefully it'll cause him to create some solid and thorough tests (improving the project) and make him better at writing tests for when he re-integrates into core development.
edit> fulfull the requirements of the software meaning that he's not just writing tests to purposely break the code when the code never intended or needed to take that test case into account.
If your colleague lacks experience writing tests maybe he or she is having difficulty testing beyond simple situations, and that is manifesting itself as inadequate testing. Here's what I would try:
Spend some time and share testing techniques, like dependency injection, looking for edge cases, and so on with your colleague.
Offer to answer questions about testing.
Do code reviews of tests for a while. Ask your colleague to review changes of yours that are exemplary of good testing. Look at their comments to see if they're really reading and understanding your test code.
If there are books that fit particularly well with your team's testing philosophy give him or her a copy. It might help if your code review feedback or discussions reference the book so he or she has a thread to pick up and follow.
I wouldn't especially emphasize the shame/guilt factor. It is worth pointing out that testing is a widely adopted, good practice and that writing and maintaining good tests is a professional courtesy so your team mates don't need to spend their weekends at work, but I wouldn't belabor those points.
If you really need to "get tough" then institute an impartial system; nobody likes to feel like they're being singled out. For example your team might require code to maintain a certain level of test coverage (able to be gamed, but at least able to be automated); require new code to have tests; require reviewers to consider the quality of tests when doing code reviews; and so on. Instituting that system should come from team consensus. If you moderate the discussion carefully you might uncover other underlying reasons your colleague's testing isn't what you expect.
# jsmorris
I once had the senior developer and "architect" berate me and a tester(it was my first job out of college) in email for not staying late and finishing such an "easy" task the night before. We had been at it all day and called it quits at 7pm, I had been thrashing since 11am before lunch that day and had pestered every member our team for help at least twice.
I responded and cc'd the team with:
"I've been disappointed in you for a month now. I never get help from the team. I'll be at the coffee shop across the street if you need me. I'm sorry i couldn't debug the 12 parameter, 800 line method that just about everything is dependent on."
After cooling off at the coffee shop for an hour, i went back in the office, grabbed my crap and left. After a few days they called me asking if I was coming in, I said I would but I had an interview, maybe tomorrow.
"So your quitting then?"
On your source repository : use hooks before each commits (pre-commit hook for SVN for example)
In that hook, check for the existence of at least one use case for each method. Use a convention for unit test organisation that you could easily enforce via a pre-commit hook.
On an integration server compile everything and check regularely the test coverage using a test coverage tool. If test coverage is not 100% for a code, block any commit of the developer. He should send you the test case that covers 100% of the code.
Only automatic checks can scale well on a project. You cannot check everything by hand.
The developer should have a mean to check if his test cases covers 100% of the code. That way, if he doesn't commit a 100% tested code, it is his own fault, not a "oops, sorry I forgot" fault.
Remember : People never do what you expect, they always do what you inspect.
First off, like most respondents here point out, if the guy doesn't see the value in testing, there's not much you can do about it, and you've already pointed out that you can't fire the guy. However, failure is not an option here, so what about the few things you can do?
If your organization is large enough to have over 6 developers, I strongly recommend having a Quality Assurance department (even if its just one person to start). Ideally, you should have a ratio of 1 tester to 3-5 developers. The thing about programmers is ... they are programmers, not testers. I have yet to interview a programmer that has been formally taught proper QA techniques.
Most organizations make the fatal flaw of assigning the testing roles to the new-hire, the person with the LEAST amount of exposure to your code -- ideally, the senior developers should be moved to the QA role as they have the experience in the code, and (hopefully) have developed a sixth sense for code smells and failure points that can crop up.
Furthermore, the programmer that made the mistake is probably not going to find the defect because its usually not a syntax error (those get picked up in the compile), but a logic error -- and the same logic is at work when they write the test as when they write the code. Don't have the person who developed the code test that code -- they'll find less bugs than anyone else would.
In your case, if you can afford the redirected work effort, make this new guy the first member of your QA team. Get him to read "Software Testing In The Real World: Improving The Process", because he obviously will need some training in his new role. If he doesn't like it, he'll quit and your problem is still solved.
A slightly less vengeful approach would be let this person do what they are good at (I'm assuming this person got hired because they are actually competent at the programming part of the job) , and hire a tester or two to do the testing (University students often have practicum or "co-op" terms, would love the exposure, and are cheap)
Side Note: Eventually, you'll want the QA team reporting to a QA director, or at least not to a software developer manager, because having the QA team report to the manager who's primary goal is to get the product done is a conflict of interest.
If your organization is smaller than 6, or you can't get away with creating a new team, I recommend paired programming (PP). I'm not a total convert of all the extreme programming techniques, but I'm definitely a believer in paired programming. However, both members of the paired programming team have to be dedicated, or it simply doesn't work. They have to follow two rules: the inspector has to fully understand what is being coded on the screen or he has to ask the coder to explain it; the coder can only code what he can explain -- no "you'll see" or "trust me" or hand-waving will be tolerated.
I only recommend PP if your team is capable of it, because, like testing, no amount of cheering or threatening will persuade a couple of ego-filled introverts to work together if they don't feel comfortable doing so. However, I find that between the choice of writing detailed functional specs and doing code reviews vs. paired programming, the PP usually wins out.
If PP is not for you, then TDD is your best bet, but only if its taken literally. Test Driven Development mean you write the tests FIRST, run the tests to prove they actually do fail, then write the simplest code to make it work. The trade off is now you (should) have a collection of thousands of tests, which is also code, and is just as likely as production code to contain bugs. I'll be honest, I'm not a big fan of TDD, mainly because of this reason, but it works for many developers who would rather write test scripts than test case documents -- some testing is better than none. Couple TDD with PP for a better likelihood of test coverage and less bugs in the script.
If all else fails, have the programmers equivalence of a swear jar -- each time the programmer breaks the build, they have to put $20, $50, $100 (whatever is moderately painful for your staff) into a jar that goes to your favorite (registered!) charity. Until they pay up, shun them :)
All joking aside, the best way to get your programmer to write tests is don't let him program. If you want a programmer, hire a programmer -- If you want tests, hire a tester. I started as a junior programmer 12 years ago doing testing, and it turned into my career path, and I wouldn't trade it for anything. A solid QA department that is properly nurtured and given the power and mandate to improve the software is just as valuable as the developers writing the software in the first place.
This may be a bit heartless, but the way you describe the situation it sounds like you need to fire this guy. Or at least make it clear: refusing to follow house development practices (including writing tests) and checking in buggy code that other people have to clean up will eventually get you fired.
The main reason junior engineers/programmers don't take lots of time to design and perform test scripts, is because most CS certifications do not heavily require this, so other areas of engineering are covered further in college programs, such as design patters.
In my experience, the best way to get the junior professionals into the habit, is to make it part of the process explicitly. That is, when estimating the time an iteration should take, the time of design, write and/or execute the cases should be incorporated into this time estimate.
Finally, reviewing the test script design should be part of a design review, and the actual code should be reviewed in the code review. This makes the programmer liable for doing proper testing of each line of code he/she writes, and the senior engineer and peers liable to provide feedback and guidance on the code and test written.
Based on your comment, "Showing that the design becomes simpler" I'm assuming you guys practice TDD. Doing a code review after the fact is not going to work. The whole thing about TDD is that it's a design and not a testing philosophy. If he didn't write the tests as part of the design, you aren't going to get a lot of benefit from writing tests after the fact - especially from a junior developer. He'll end up missing a whole lot of corner cases and his code will still be crappy.
Your best bet is to have a very patient senior developer to sit with him and do some pair programming. And just keep at it until he learns. Or doesn't learn, in which case you need to reassign him to a task he is better suited to because you will just end up frustrating your real developers.
Not everyone has the same level of talent and/or motivation. Development teams, even agile ones, are made up of people on the "A-Team" and people on "B-Team". A-Team members are the one who architect the solution, write all the non-trivial production code, and communicate with the business owners - all the work that requires thinking outside the box. The B-Team handle things like configuration management, writing scripts, fixing lame bugs, and doing maintenance work - all the work that has strict procedures that have small consequences for failure.