The online system used to apply, do the tests and book an interview is very sleek and works well. Having performed well enough in the online tests I was invited to their London office for an interview, skipping the phone interview stage. They immediately paid my expenses upon arrival and made me feel welcome and comfortable. The interview consisted of a traditional interview stage and 2 tests, one was write code to get a robot out of a maze based on their own assembly style language the other was in Ruby. I managed to finish both the tests with working solutions and felt I did well. The whole process took about 1.5hrs. Ultimately they emailed me saying they thought I asked too many questions about the code, felt this was a bit unfair as they prompt you to ask questions and talk to you about the tests while doing them but apparently I didn't wizz through it all in minutes without a discussion on a test with languages I've never used :| They're clearly a good company and the application process is well refined, I do get the feeling that they don't have many job openings available based on the lack of offers people seem to get on glassdoor and just how strict the hiring requirements seem to be. If you're confident about getting the job have a go but wouldn't get your hopes up!