DE Shaw Interview Experience - Lead / Principal
Summary
I went through multiple interview rounds at DE Shaw for a Lead/Principal role, covering behavioral, coding, concurrency, and several system design sessions.
Full Experience
Round 1
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Behavioral & Leadership:
- questions around review processes for designs, dealing with disagreements, etc.
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Coding: A city which consists of buildings (skyscrapers) of different floors in a straight line, ex: floors arr = [5, 2, 9, 3]. You can only demolish some floors from a building, but can’t construct them. But the floors demolished will add into your cost. If a building is entirely demolished, it disappears from the city. Bring all the buildings to the same height by using Least Demolition Cost. O(n*log n) time, O(1) space.
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Java Concurrency:
- Write two threads, one thread only prints odd numbers, one thread only even. But eventually the numbers should be printed in sequential order.
- Multi-threading Trivia like no. of ways of creating a thread, difference between thread created by extending thread and implementing runnable.
- Design a concurrent hash map.
On-site Interviews
Round 1
- LLD of Food Delivery app like Swiggy / Zomato.
- LLD of a Job Scheduler Library, where you submit a job, and give a schedule for running repeatedly, like every 30 minutes, every 6 hours, etc.
- Behavioral, Leadership, Management:
- Questions around disagreement with stakeholders, push-back scenarios, etc.
Round 2
- Something similar to Leetcode 380
- LLD of Uber: More in-depth questions about ride matching, and improving satisfaction for users.
- Behavioral, Leadership, Management:
- Situations and experiences about a report underperforming, taking initiative for a project, etc.
Round 3
- HLD Google Docs: More in-depth conversation about OT layer.
- LLD of a coupon management system.
- More questions about past projects. Data Models, designs etc.
- Behavioral, Leadership, Management:
- Questions around keeping senior leadership, execs in loop for a project, juggling multiple responsibilities per day, etc.
Round 4 - HR Round
- What motivates you
- What kind of role do you see ideal
- Rate these while choosing your next job: Brand Name, Role, Pay, Location, etc.
- Other trivial questions.
PS: Absolutely will not respond to questions like "how did you apply?". Please stick to the post in discussions. I was cooked with lot of LLD questions, and apparently that's the norm there.
Interview Questions (8)
Least Demolition Cost to Equalize Building Heights
Given an array representing the number of floors in each building (e.g., floors = [5, 2, 9, 3]), you may demolish any number of floors from any building (you cannot add floors). Demolished floors add to your cost. If a building is completely demolished, it disappears. The goal is to make all remaining buildings have the same height while minimizing the total demolition cost. Expected solution runs in O(n·log n) time and O(1) extra space.
Print Odd and Even Numbers with Two Threads in Sequence
Write two threads: one prints odd numbers, the other prints even numbers. The combined output must be in sequential order (1, 2, 3, 4, …).
Design a Concurrent HashMap
Explain how you would design a thread‑safe hash map, covering aspects such as locking strategy, handling concurrent reads/writes, resizing, and collision resolution.
Low‑Level Design of a Food Delivery App
Provide a low‑level design for a food‑delivery platform similar to Swiggy or Zomato, covering core components, data models, and interactions between services.
Low‑Level Design of a Job Scheduler Library
Design a library that allows users to submit jobs and specify recurring schedules (e.g., every 30 minutes, every 6 hours). Discuss job representation, scheduling algorithms, persistence, and fault tolerance.
Low‑Level Design of Uber‑Like Ride Matching System
Describe a detailed low‑level design for a ride‑matching service similar to Uber, focusing on request handling, driver‑rider matching, scalability, and user‑experience improvements.
High‑Level Design of a Collaborative Document System (Google Docs)
Discuss a high‑level architecture for a real‑time collaborative document editing platform, covering OT (Operational Transformation) layer, synchronization, storage, and conflict resolution.
Low‑Level Design of a Coupon Management System
Create a low‑level design for a coupon management system, including coupon generation, validation, expiration, and application to orders.