Initial aptitude test, around 20 questions, takes less than 5 min. Then invited to attend the pre-screening interview with the Head of HR . After that received a logical reasoning/stats test, which took bit above 1h. After the test, I was invited to the main technical interview, which consisted of going through previously submitted test, followed by completing live python test. Interview was really pleasant, and I've really learnt a lot! Interviewers were incredibly nice and helpful with feedback. Unfortunately I've failed on the test, since some of my knowledge was quite rusty, but overall I had really positive experience, and despite the obvious failure, I left interview with a relatively good mood!