The interview question was to display select stores using a python web framework, use an external dependency for geolocation, and filter stores within a given radius, while sorting them from north to south.
I had to make a few assumptions as all the constraints weren't specified. I submitted an implementation and a few tests. On-site, the interviewers asked me about the assumptions I had made and to explain my implementation. They also asked me what I would do to convert the program to a web service. I got mixed feedback for this stage: seems like I didn't give the ideal answers
I believe that testing is always required and if you're going to test something manually you may as well write a test for it and make it re-usable. I have a long history of writing tests, and trying to get the companies I work for to invest more into automated tests, to improve code quality and reliability.