I used a recruitment agency (but you can also apply directly). The process is:
[1] Telephone interview
[2] Technical test (OO PHP)
[3] Face-to-face interview
I did quite well on the telephone interview which, as mostly a listening exercise, was probably quite hard to fail!
The technical test - which involves writing some OO PHP around a bit of a spec - is something that I seemingly did *just OK* on, but managed to get through to the face-to-face interview.
The face-to-face was quite a grilling though it did have some interesting questions. My interviewer arrived about 15 minutes late with no apology or explanation - off to a bad start! The experience was quite negative for me as the interviewer seemed bothered to be there and didn't really ask about my skills or experience, especially how that would transfer to the role. It was a rather stilted, mechanical exchange.
My biggest red flag was that my interviewer didn't seem to have a good answer for "should I get the role, what projects would I initially be working on?".