Written test first and then if successful oral discussions. There are further rounds if successful. The written test can be taken from pretty much everywhere but I took it from London.

I applied through a recruitment agency and the entire process took a bit, but this was due a busy period on my side. There was a test in which there are many probability and statistics questions. Of course I can not say more due to confidentiality agreement. After that there was an interview from junior quants.

Fist a written test, then a couple on-site technical/skills interviews. Final round of interviews with management. I had a positive experience with the technical interviews. I was treated well and the interviewers are quite capable.