YOE: 6
Update: Due to NDA, Not sharing the exact questions.
Overall interview experiance with facebook was very good and they follow a highly systematic approach for conducting interviews. It consisted of following stages :-
One telephonic round.
4 onsite rounds in London.
General Tips:
- Each round is of 45 mins and 40 mins are given for problem solving and time schedule is fixed, in case interviewer gets late or your interview starts late, you willl loose the time.
- For coding rounds, I had heard from my friends that one has to complete 2 questions in 40 mins with most optimal solution coded (not even suboptimal is accepted) and rare case 1 question if it is hard.
Telephonic Rounds
It consisted of 2 questions and lasted 45 mins. Question was related to number format change (Difficulty Level : Medium). I solved using hashmap. I completed the question in 30-35 mins, I had 5 minutes for the next question. I asked the interviewer to ask me the next question ASAP as I had notion that without 2 questions I won’t go through.
He said he will ask an easy one since there were just 5-7 mins left, it was related to merging in place 2 sorted arrays in one go. I completed it in no time.
After couple of days i got mail for HR that they want to fly me to onsite. I scheduled a date which is after 1 month. But had to reschedule it due to some problems. After 1month and 3 weeks I appeared for onsite.
Onsite Rounds(2 coding rounds, 1 sys design and 1 behavioural)
Round 1: Coding round (45 min).
The interviewer told me in case I know the question, I should let him know.
First question was a medium related to array manipulation, I told him as I knew it. He asked the approach and moved on.
Other Questions were :-
A question realted to Palindromes. (Difficulty Level: Easy)
A question related to string search (Difficulty Level: Medium).
Discused the approach, edges cases and coded in time.
Round 2: Behavioural round
This round consisted of only behaviour questions and not technical questions. Question were all around my previous experiences, the things I did wrong, the things I did well. How I felt leading a project/ as a team member and many more.
I had gone into some technical details of the experiences, I think that backfired when I got the review.
Behavioural round is really important to get a senior position. It decides wethere you’ll get and e4 or e5. Be honest and confident to do well.
After this had lunch with a fb engineer, talked about fb, london and other stuffs.
Round 3: Design round (45 min).
Interviewer clearly mentioned that there will be an ambigous problem and I have to clear the things and derive the discussion. While prepraring I felt 40 minutes are more than enough but in the interview It appeared I wanted to convey more but had less time, but overall this round well.
I found this approach to be very useful: https://leetcode.com/discuss/career/229177/My-System-Design-Template
Round 4: Coding round
Interviewer was late by 5-7minutes or so and I only had 30 minutes for two questions as 5 minutes are reserved for you to ask questions to interviewer about fb.
Question were:
Related to n-ary tree (level : medium)
custom sort(level: medium)
Discussed the appraoch, optimised it.
Luckily I had practice with similar questions and was able to solve them in the given time with all edge case covered.
Since I had another offer, asked them for results in 2 days. Recruiter came back saying that the rounds went well but the level doesn’t match e5 for which they were targetting, though were happy to offer e4 as when they get headcount for e4 and after 1 month, they gave the offer. System design and behavioural and very important to get a higher level.