It started with a requirement for writing about my favourite recent challenge and how I've solved it. Then I've gone through a phone screen interview, in which they asked about logical, general IT problems, like how to make a list to which any modification costs a constant minimal effort. Then followed an on-site interview to which I was given a homework in the previous day to present at the interview. We discussed my homework, then came a general full-stack tech interview with questions about database relations, java features, design patterns.