I used interviewing.io and pramp really heavily in my most recent job search. I found that interviewing.io interviews were of a much higher quality in general vs pramp which was pretty hit and miss, some interviewers were well prepared and helpful and some clearly checked out after their half of the interview. But I ended up using pramp a lot more since they had unlimited interviews and used interviewing.io as benchmarks to see how close I was to where I wanted to be. Recommend them both!

practicecodinginterview seems to be extremely expensive. who pays almost 1000$ for 5 interviews? the way i see these practice interviews is so that i get used to dealing with strangers and rid myself of nerves. why the hell would anyone pay so much for some practice is beyond me even if its "guaranteed" to be someone at FAANG that interviews you. anybody thats a stranger is more than enough for me. and then LC on the side if need be.

I have used both interviewing.io and pramp. I think interviewing.io is of better quality. But I do think there is value for pramp since it is a mutual interview and we can see how others are answering questions. It helped me a great deal in improving system design interviews.

Pramp is a "mutual interview". You interview someone and they interview you within the same session. This is a one-sided interview.