Meta | E4 | London | July 2024 [Offer]

Meta E4

Current Position: Software Engineer 2 at Amazon Years of Experience: 3.5

I applied via Meta's career portal and received a response from HR. The first round was a recruiter screening.

• Recruiter Screening: 40 mins - Discussion about past work experience, tech stack, current projects, deliveries, and impact. Be prepared to discuss your resume.

Following the recruiter screening, I completed a technical screening round.

• Technical Screening: 45 mins (5 mins introduction + 35 mins coding + 5 mins Q/A)
  1. Nested List Weight Sum
  2. Basic Calculator II

I completed optimized solutions, including dry runs, test cases, time complexity, and space complexity analyses for both questions.

After a week, I was invited for onsite rounds.

• Coding 1: 45 mins (5 mins introduction + 35 mins coding + 5 mins Q/A)
  1. Lowest Common Ancestor of a Binary Tree III
  2. LRU Cache

I experienced some difficulty explaining the mathematical proof of a traversal technique in the first question; however, the rest went well.

Verdict: Hire

• Coding 2: 45 mins (5 mins introduction + 35 mins coding + 5 mins Q/A)
  1. Given an array of integers, return the index of one of the largest elements, chosen uniformly at random.
  2. Plan a round trip between two cities with minimum flight cost. From the departure city to the destination city, the fees are stored in array D[]. From the destination city to the departure city, the fees are stored in array R[]. Both arrays should have equal length, and the index corresponds to dates. D: [10, 8, 9, 11, 7] R: [8, 8, 10, 7, 9] The minimum cost will be D[1] + R[3] = 15

I covered brute force, optimized solutions, dry runs, test cases, time complexity, and space complexity for both questions.

Verdict: Strong Hire

• System Design: (5 mins introduction + 35 mins design + 5 mins Q/A)
  Design a component in the Facebook app to show the top k trending hashtags of the last 12 hours. This data will be refreshed every hour. Hashtags from posts, likes, and comments will have different weightage.

I addressed functional and non-functional requirements, estimates, APIs, data model, and high-level design diagrams, along with follow-up questions. I did not cover low-level component details, data aggregation logic, or component interaction.

Verdict: Mixed Signal

• Behavioral: 45 mins
  Standard behavioral questions, answered using the STAR method.

  Verdict: Strong Hire

Follow up round

A follow-up system design round was conducted due to the mixed signal from the initial system design round.

• Design a multiplayer game like chess that can scale up to 1B concurrent players. Public matching is not allowed; only matching with friends is supported. A matching algorithm for friends is required. The ranking board should update immediately after a win/loss.

I covered functional and non-functional requirements, estimates, APIs, data model, high-level design diagram, trade-offs between NoSQL and SQL, real-time and non-real-time ranking boards, Apache stream processing, MapReduce jobs, and scalability.

Verdict: Strong Hire

I received a job offer for the E4 role. The offer process included team matching and negotiation. I received the final offer letter.