Facebook recruiter emailed me and it was a perfect match for my profile. So I started digging up glassdoor and other sites on what to expect. And then I turned to leetcode and started studying common algorithms questions. Call with recruiter: She was great, explained the role in detail, cared whether it aligns with my interest and my profile. And mentioned that there will be 2 phone interviews and then an on-site interview. First interview and second phone interview went very well, I cannot imagine anything that I would have done better in these two interviews. But got an email from recruiter that they would like to go with the third phone screen before they can call me on-site. Third interview: Interviewer explains me a problem which is similar to a 3sum problem and asks me to write a solution for it. I hadn't 'summarized' the solution and, this how it goes between me and the interviewer: Me: "The problem you are explaining is quite similar to a well known problem of 3sum" She: "Yes" Me: (explained the approach,the time and space complexities associated with it of 3sum) She: "Lets see some code" (I start writing the code and continuously explain what I am doing. Once I write the core algorithm I told her) Me: "So this is the core algorithm, and we just need to add null checks and add corner cases." She: "OK lets go thru your algorithm, how will it behave in (this corner case)" Me: "As I mentioned, this is the core of the algorithm, we still need to do null checks and consider corner cases." I add null checks and 2 corner cases and then we started going through lot of scenarios, my code holds good in all of them and the interview continues like normal. So, I thought I had aced this interview too. I get an email from the recruiter saying they will pass for now. I ask for the feedback and they mention that I used 'brute force method' to implement (a certain corner case). I said to myself, I was still implementing the algorithm, ofcourse you will run through many scenarios before you call the code done. But I guess others out there are right, interviewers at facebook wants bookish knowledge. It doesnt matter how many years of experience, you still need to topple all the algorithm books and go summarize leetcode before the interview. Your experience, your profile, the projects that you have worked on and your 'non algorithm' technical knowledge doesnt matter or may be it matters only after the fact that you have successfully summarized algorithms. And, its not like I am disillusioned.I am a Senior dev, in my early 30s working for a quite good corporation in the valley and I have been interviewing, hiring and mentoring junior dev from many many years now. And the fact that I didnt even clear a phone screening is quite interesting to me. I am quite disappointed and it makes me think: Did the recuriter reached out to me even though there were none actual positions open? Or did it get filled up somewhere in the middle and I got a 'false' reason for rejection?