Background: 4 years distributed systems experience.
Of all the interviews I gave in last one year this was one of the worst. I met an interviewer twice, once in my telephonic screen I and again on virtual onsite. He blabbered about his achievements for 20 minutes without any break or asking me any questions. Later part of the interview he was very rude.
Telephonic Screen 1
20 minutes interviewers achievements. Next 20 minutes undermining my experience. next 20 minutes implement Circular Queue, here also he was asking very non-sense questions.
Miracle he gave green light and I was scheduled for next telephonic screen. But I made sure my experience reached the recruiter, he apologized and said he will let the team know.
Telephonic Screen 2
This interviewer was really cool. He asked me very unique question of calculating and updating excel sheet formulas, you have a display cells and formula cells. assume formula cells are immutable and depends on multiple display cells. You can update the values in display cell, after doing so you have to update all formula cells depends on that.
Got a green light again for the Onsite.
Virtual Onsite Round 1
You are given with a machines connected in a straght line (A<->B<->C<->D) each machine can talk to the neighbour. Can you implement functions such that you print number of machine in the topology.
Virtual Onsite Round 2
- Count set bits.
- Come up with a Regular expression given list of strings. (car, bar, bat, cat,cartoon) : output: ( ba(r|t), ca(r|toon|t)). solved with recursion and prefix tree.
- design throttling service. very briefly talk about components.
Virtual Onsite Round 3
Design Chess. I think since the begining everything went bad, meaning my preparation is toomuch for this round and I can't stop over engineering many modules and I though this round went below average.
Virtual Onsite Round 4
Serializing N-ary tree. Twist is fewer memory. I came up with solution of Node(byte), SizeofChildren(byte), Children(next bytes).
Virtual Onsite Round 5
Again Apple was trying to test my patience with the same interviewer whom I got in telephonic 1. This time he started off fine. Question was simple use Trie and solve Work break. I started implementation using recursive idea, he kept on my back stopping me that I am writting ugly code (Problem solving or writing a code you generally tend to start with not so clean codeand improvise later after having a workable solution), I think he hit my morale multiple times like this and I have ended up keeping a bug. unlike 3 coding rounds above I came across very new questions and solved them. So please my request to fellow technichal engineers that please help the candiadate to let go off nervousness don't put extra stress to hit the morale.
Closing comments
Out of 5 rounds 3 rounds went excellent and 1 round average and 1 round below average. I was very low since I screwed up 3 interviews before this and yeah I received the rejection on my B'day. But after 3 days I heard very pleasant news: E5 offer from Facebook. So never loose hope there is always light at the end of tunnel. keep practicing and interviewing. :-) Hope this post helpts. Here is my FB experience: https://leetcode.com/discuss/interview-experience/693141/nda-facebook-e5-seattle-jun-2020-offer/586384