The first interview was on HireView, that is a recorded interview. You have 30 seconds to prepare each questions, and have 3 minutes to answer. You get to present yourself a little, then have a few software questions. It ends with 2 C programming 'challenges', simple enough C tests that are not timed - the interface is similar to Codingame, with a description of the requirements and a few tests to pass.

The second interview was a face to face on Skype, as I did not live in the UK. The interviewers first ask you about your knowledge of C and programming, and then go through a Google doc with either small C implementations you have to do or C programs you have to debug - you have to explain your line of thought throughout this part. If you have a few difficulties, the interviewers try and guide you towards the answer, or at least a way to reach a correct result.

The topics included C string manipulation, simple C data structures, and the C volatile keyword.