Long and tedious process. I applied through their website and a recruiter reached out immediately. There was 1 take-home, 3 tech/case interviews and 1 final round with a partner. Instead of doing all rounds in 1 take, they broke down to 4 different meetings and each meeting was 1,2 weeks apart. It dragged the interview to months, instead of 1,2 weeks.
The 1st tech interview was coding interview, which consisted of leetcode easy/med questions. The next 2 tech case interviews were system designs where they would ask you to build/scale twitter or facebook app.
My verdict: Don't take this too serious, treat this job application like your 2nd/3rd options while you are applying to different jobs. Why?
1st, Even you may do well in all rounds, but they would drop you for no particular reason. I went through all rounds and had an awesome chat with the partner, yet I failed and they said I was not technical enough. You should have not talk to the partner unless you have passed all tech rounds.
2nd, the process is long, and if you think about making a big jump in tech, think interviewing with tech companies like FAANG, they have better interview processes, much faster and have good feedback.