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Real Interviews

See also: Real Exams



For 2024


  • Many Linux Foundation Knowledges

For 2023


  • Many CS fundamental questions (e.g., what is a Hash Table (pros/cons)?)
  • isPalindrome with a few edge cases


  • technical design of a class registration system (higher level engineering)
  • technical design of a package manager proxy server (multithreading)


  • 1 Q on removing adjacent duplicates
    • simple O(n2)O(n^2) algorithm
    • improved to O(n)O(n) algorithm using stack
    • can improve space complexity from now on but cannot improve time complexity.
  • 1 Followup Q on removing length adjacent duplicates arbitrarily
    • O(nk)O(nk) algorithm
    • Had even more time left, so I discussed with the interviewer and improved to O(n)O(n) algorithm 😃
  • Learned that Grammarly has internal projects, Readerly (summarizing) and Speakerly (Generative Intelligence)

Palantir with Karat

  • 3 basic questions (analyzing algorithms and complexities)
  • 3 Leetcode Easy to Medium Problem
    • Question involved constructing trees and traversing them
    • Each question is built on top of previous queries, getting gradually harder.
    • However, the most challenging question was still Leetcode Medium level.

Duolingo with Karat

  • 3 basic questions (analyzing algorithms and complexities)
  • 1 Leetcode Hard level question
    • Involved in Game State Change, Constructing Adjacency List of Game States, and Pathfinding
    • Given a Game Board, find a list of moves from the start state to the end state


  • 2 1-hour interview
    • 1 conceptual, technical design (data pipelines & tradeoffs)
    • 1 conditional BFS problem