I applied through a recruiter. The process took three months.

It was online, quite long, but also flexible. I didn't mind the delay, as sometimes it was because of my personal things too. The recruiter and the interviewers were very nice and open, with polite and relaxed interviews.

I can't really say, but anyway, there isn't much to prepare in advance. The recruiter clearly states the next stage you have to finish in the email—no surprises, including the parts where some technical knowledge is in focus (describing thought process > pure coding skills)—and you can ask them in case of any doubt. They respond fast.

Also, after CV and cover letter screening, there are logical questions that truly cannot be prepared for; knowing English well and being concentrated is the only advice. Good luck!

Also, the whole time there are a lot of personal questions to assess personality fit, both written and in interviews. Some honest introspection beforehand is useful to know your strong points and interests.