SDE-2 at Amazon

How it went

What they would tell you

How to prepare

Their background

Round by round

1. 1

   Technical Round 160 min

   Asked to explain the approach for finding the n-th ugly number, followed by optimizing the solution. Leadership Principle (LP)

   • Tell me about a time when you made a decision with limited information. How did you handle it?
   • How do you prioritize tasks when multiple deadlines are approaching?
   • Ugly Number
2. 2

   Technical Round 2 (Low-Level Design)60 min

   Design a Movie Ticket Booking System

   • Seat selection, booking, concurrency, and handling cancellations.

   • My focus was on clear class design (Movie, Show, Theater, User, Booking), idempotent APIs, and locking strategies (how to avoid double-booking seats). Discussion:

   • “How do you ensure high availability during peak times?”

   • “What happens if the user loses internet mid-booking?” Leadership Principle:

   • The interviewer drilled into Insist on the Highest Standards (Did I ever recall a time a project slipped? How did I bounce back?) and Deliver Results (How did I unstick a stuck project?)

3. 3

   Technical Round 3 (High-Level Design)60 min

   Design Slack real-time messaging, channels, user presence, history.

   • My approach:

   • API Design: REST + WebSocket endpoints for real-time updates.

   • Data Model: Users, channels, messages, read receipts.

   • Scalability: Sharding, caching (Redis), pub-sub (Kafka/SQS), and handling millions of users.

   • Failure Modes: What if a data centre goes down? How do you handle message loss? Follow-up:

   • How would you implement search across all messages?

   • How do you balance eventual consistency with user expectations? LP:

   • Tell me about a time when you had to take ownership of a challenging situation at work. How did you handle it?

   • How do you earn trust in a team?

4. 4

   Bar Raiser Round60 min

   In the Bar Raiser round, I was given problem related to designing in-memory file system Problem required designing a system that could mimic file operations like ls, mkdir, addFile, and readFile in memory, with the constraint that all operations should be efficient. I started with basic structure, including directories, files, and paths. Then how to store files in memory, ensuring read/write operations.

   • Designing in-Memory file system
5. 5

   Offer Discussion60 min

   I was given a detailed breakdown of salary structure, bonus eligibility, and benefits (healthcare, stock options, ...)

What came up