Submitted CV and cover letter online. A few weeks later was invited to an assessment day they were holding. This consisted of a presentation from them about the company, then two coding interviews and a final personal interview. The coding interviews were done in pairs: the first was to analyse a section of code (with your partner) and discuss what you think the code achieved. The second was to write some code to do something, and then read a separate pair's code and analyse what you think their code did.