D. E. Shaw

1. 1

   Coding test

   Online coding assessment, 3 questions
   HackerRank80 min3 questionsmediumeliminatory

   strings · simulation · queues · hash maps · binary search · prefix sums · greedy · stacks · trees

   Duration 80 min in one account, 90 in the other. One account had locked per-question timers (20/30/30 min) and fixed order; the other free order. About 12 hidden cases. Around 2.5 solved questions needed to qualify. Other account rates questions about 1200 to 1300 on Codeforces.

2. 2

   Technical interview

   Interview round 1: DSA, design and ML basics
   In person, pen and paper (one account); online (other)75 minhard

   trees · DFS · design · AST-based similarity · regression metrics · logistic regression vs neural nets · monotonic stack · FastAPI · DBMS · OOP

   Two interviewers, no introductions, direct questions; interviewers were blunt and applied pressure on purpose. About 75 minutes in one account.

3. 3

   Technical interview

   Interview round 2: DSA and language fundamentals
   60 minhard

   inversion counting · divide and conquer · dynamic programming on strings · Python iterators and generators · decorators · dunder methods · slots · GIL · basic system design

   Interviewers wanted the path from brute force to optimal explained, not just the answer. One interviewer was a lead engineer from the Hyderabad office. Interviews ran at midnight in one account.

4. 4

   Technical interview

   Interview round 3: short data structure and design round
   30 minmedium

   custom list implementation in C++ · heterogeneous containers · prefix sums per category · text editor design

   Taken by one of the round 1 interviewers; noticeably friendlier. Only one account describes it.

Advice from candidates

54 pieces of advice, in their own words. Names removed.

• Overall the main strategy to solve questions in this OA was speed. I was able to solve all three and you needed around 2.5 questions solved to qualify for interviews.

  Online assessment · 2025-26

• The interviewers exerted a lot of pressure during this interview and challenged everything pretty bluntly (borderline rude sometimes). Make sure to not lose your cool during the interview as they do this on purpose.

  interview · 2025-26

• The main thing to keep in mind is to not jump directly into the optimal approach. The interviewers emphasized a lot on how I arrived at this approach and you need to explain yourself well in this case. Just knowing the optimal solution directly won’t do as it seems very out of the blue.

  interview · 2025-26

• This section required you to be thorough with your language fundamentals. Use resources like interviewbit to go through commonly asked questions but also make sure that you know the inner workings of your language pretty well and not just how to do DSA in it.

  interview · 2025-26

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Question patterns reported

The kind of problem, not the problem itself. Our practice questions are written to match these patterns.

• Codingcount substrings whose mapped digit sum divides length, n up to 5000
• Codingsimulate single scanner with direction-priority rules, two queues
• Codingnearest sensor in same row or column using sorted lists and binary search
• Codingprefix sums with greedy
• Codingbracket sequence with stack
• Codingtree problem
• Technicaltree: maximise total travel distance, per-edge contribution from subtree sizes
• Technicaldesign code plagiarism detector robust to renaming and dead code
• Technicalmonotonic stack problem
• Technicalcount pairs with earlier larger element, merge-sort based
• Technicalmin moves to front or end to turn a permutation string into another
• Technicalmonotonic stack or optimisation questions from DSA
• Technicalimplement Python-like list in C++, then support mixed types
• Technicalrange count of a category with few categories via prefix sums
• Technicaldesign text editor with linked list and character index
• Codingcount subsets with negative product, modulo answer
• Codingkth smallest 10-digit number, no equal adjacent digits
• Coding3D DP on house colouring with neighbourhood limit
• Technicalfirst occurrence in array with adjacent difference at most one
• TechnicalO(1) insert, delete, search, random element structure
• Technicalfind peaks in array
• Technicaldetect cycle in linked list
• Technicaldelete whole binary tree quickly
• Technicaldesign browser history with reverse print, delete, search