Facebook interview: Case study

March 9, 2022

Here is the article. 

Facebook [OFFER - ACCEPTED]

• Position
  • Rotational Software Engineer
• Application
  • Interviewed with FB in 2018 and got rejected. Recruiter followed up with me a year later and asked if I was interested in interviewing again. At the time I wasn't but then several months later I followed up with that recruiter and was able to schedule a call to start the interview process again
• Stage 1: Call with recruiter
  • Quick and straightforward conversation about the position, the company, my background/experience, and the interview process
• Stage 2: Tech Phone Screen
  • Coding Challenge 1
    • "Easy" level leetcode question
    • Return the sum of an array that contains either numbers or other arrays of numbers, and multiply the total of each array by its nested depth
  • Coding Challenge 2
    • "Medium" level leetcode question
    • Given a string with alphanum characters and open or close parentheses, remove the minimum number of parentheses necessary to ensure all parentheses correctly close (only "(" and ")" are used, no brackets or curly braces)
• Stage 3: Virtual Onsite
  • Interview 1: Coding Challenge
    • Challenge 1
      • Write a function that accepts an array of numbers and returns the length of the longest monotonic subsequence
    • Challenge 2
      • Write a function that accepts a tree and returns the length of the longest path between any two nodes
  • Interview 2: System Design
    • Problem
      • You're working on a music streaming app. How would you build a feature to show users their top 10 most-played songs each week?
      • Interviewer had follow-up questions, and also asked about things like how to measure the feature's success, and what other similar/related features can be built on top of this
  • Interview 3: Behavioral
    • Was asked several behavioral questions about how I would handle a certain scenario or to talk about past challenges/successes
  • Interview 4: Coding Challenge
    • something like leetcode #460 - subarray sum equals k
• Interview Result
  • Received offer for Rotational Software Engineer E4
• Interview Experience
  • Extremely Positive
  • Recruiters were outstanding
  • Interviewers were really experienced
  • All of the discussions felt like real, down-to-earth conversations, as if we were working a problem together
  • FB was my #1 choice so I accepted the offer and then declined my other offers/candidacies