Struggling with sorting data in ember - ember.js

Question

I have an ember route that gets the following data:
return this.store.findAll('servicerequest');
One of the fields is a date field called created_at that I am trying to sort by.
Here is my servicerequest controller:
import Controller from '#ember/controller';
import { sort } from '#ember/object/computed';
export default Controller.extend({
appName: 'Service Requests',
sortAscending: false,
sortDefinition: ['created_at:desc'],
sortedRequests: sort('servicerequest', 'sortDefinition')
});
Here is the hbs section where I am outputting the data:
{{#each sortedRequests as |servicerequest|}}
{{servicerequest-list status=servicerequest.status srdescription=servicerequest.srdescription priority=servicerequest.priority created_at=servicerequest.created_at
current_user_id=servicerequest.current_user_id servicerequestId=servicerequest.id}}
{{/each}}
I have not been able to get anything to sort by the created_at field desc. What am I doing wrong?
UPDATE:
Here is my model:
import DS from 'ember-data';
export default DS.Model.extend({
requester_name: DS.attr('string'),
srdescription: DS.attr('string'),
priority: DS.attr('string'),
status: DS.attr('string'),
created_at: DS.attr('date'),
current_user_id: DS.attr()
});
The data is coming from a rails api. The created_at field is what the systems defaults to on records that is why there is an underscore.
I am using ember-cli: 3.0.2

Answer 1

So I ended up getting it working by doing this:
return this.store.findAll('servicerequest').then(results =>
results.sortBy('created_at').reverse());
Not sure if it is the best way but for now it's doing what I need.

Answer 2

Ideally any data operation should be performed at the backend.
Incase if there are any backend limitations, you can move the sorting logic snippet into the serializer. This way, any fetch call for 'servicerequest', will come sorted and redundant sorting logic can be avoided.
Something like =>
serialize(snapshot, options) {
snapshot.sortBy('created_at').reverse();
return this._super(...arguments);
}