I am writing this post to share my recent interviewing experience with Facebook.

Current experience: 5 years in software engineering in a mid-level company

I had my Facebook phone interview for the position of Software Engineer. The overall interview experience was pretty good, the interviewer asked me two coding questions:

1. Merge 3 sorted array
2. Twisted question similar to https://leetcode.com/problems/verifying-an-alien-dictionary/

I answered both the questions well. For the first question, I mentioned the interviewer a Minheap algo method and he soon denied it saying, he wanted better memory complexity. So i came up with a pointer based approach to solve it. I solved the question in 20 minutes and mentioned the time complexity of my solution. He denied my time complexity calculation and told me to recheck. After some few attempts, i finally came up with the answer (ie. o(n^2)).

Then the interviewer proceeded to the next problem. I solved the problem in just 6 minutes and gave the correct time complexity (o(n^2)). The interviewer was very happy and he told me that my solution was correct.

Since the interview went very well, i was on high hopes that I would go for the next round. But today, I got a rejection email from the recruiter. I was furious and emailed them back for the feedback, but I didnt get any reply.

What I would like to know is on what basis the they select the candidate for the phone interview ? what it takes to crack the Facebook interviews ?
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