Overall process was smooth and well structured. Recruiters were quick to follow up both after the phone interview and onsite. One of the interviewers came across as a bit rude from the minute she entered the room, and ended up failing me. Questions are not too difficult, but the bar is very high. If you know the answer beforehand, then good for you. If you take a moment to think, they will flag you as being slow, even though you solved the problem.

I was approached by Facebook recruiter so it wasn't me who applied to them. Of course I got info how great I'm and how much experience I have etc. so I decide ok let me try why not. The interview was really long, the periods between first talk then first interview and then final interview took in total almost 3 months (If I knew about it I would dump it in first place). The first talk and 2nd interview was fine, got a proper feedback etc. the guy at code interview was great we had good contact and I think I did gr8 too, after 2 days got invite fot last stage with 4 interviews. More materials to learn etc. At this stage everybody was super helpful, recruiters response was fast. Then the last stage came - 2 code interviews, system design and behavioral interview. It was all a bit exhausted. One of code review was with really unpleasant guy. He was super unhelpful. I asked few helpful questions he agreed that these are the right assumptions, but then later he was changing his mind all the time which makes me more nervous and running out of time. It looked like he was interested in solving this particular thing in very specific way only and I just wasn't able to figure out what he exactly thinks. Even though I finally found a way to what he wanted I had a strong feeling that it was still not good enough. Then there was a system design which looked very different from what facebook describes in all materials and what video you can find on youtube. It was strange because the guy wanted to write a code on system design blocks - how the functions should look like etc. etc. (yes code inside blocks). So in the end it was a mix of code interview just writing code on a white board mixed with UI blocks :/ After a couple days I got a response that they decided not to move forward. I asked if they can provide some more feedback for me so I can understand if all interviews were bad or maybe some were better or maybe I was simply bad at one etc. Something I can improve that I might be not aware of. But I never got any response nor more explanation or at least message that they cannot give me such feedback etc. nothing null, contact has been lost :/ I would expect much more from such company. So that's why unfortunately my final opinion is negative. I would not waste so much time again if I knew I would not even get a reasonable feedback from final stage. If I can learn one thing from this lesson, that would be to avoid companies who don't care what you did before, but they only focus on academic problems and lastly don't give a proper feedback.