I recently went through the interview process at Amazon for a SDE 2 Backend role and wanted to share my experience. There were 5 rounds in total — including DSA, system design (HLD + LLD), and a Bar Raiser round. Hope this helps others preparing for similar roles!
1) Round 1 — DSA + Leadership Principles
Started with two LP questions followed by one DSA problem.
LP Questions
Standard behavioral questions focused on ownership and delivering results. Prepare specific STAR-format stories from your past experience.
DSA: Course Schedule II
https://leetcode.com/problems/course-schedule-ii/
2) Round 2 — DSA + Leadership Principles
Two LP questions followed by two DSA problems.
DSA 1: Merge Intervals
https://leetcode.com/problems/merge-intervals/
DSA 2: Product of Array Except Self
https://leetcode.com/problems/product-of-array-except-self/
3) Round 3 — System Design HLD + Leadership Principle
One high-level design problem followed by one LP question.
Design: Google Docs (Collaborative Document Editing)
Key areas discussed:
- Real-time collaboration
- Operational Transformation (OT) vs CRDTs for conflict resolution
- WebSocket connections for low-latency sync
- Storage and versioning
- Delta-based storage for document history
- Snapshot + diff strategy for efficient retrieval
- Scalability — sharding by document ID, regional replication
- Presence indicators (who's editing what, cursor positions)
- Permissions and access control model
4) Round 4 — System Design LLD + Leadership Principles
One low-level design problem followed by two LP questions.
Design: Uber (Ride-Hailing System)
Key areas discussed:
- Class design — Rider, Driver, Trip, Payment, Location entities
- Trip state machine: requested → accepted → in_progress → completed / cancelled
- Driver matching algorithm — geospatial indexing (quadtree / geohash)
- Surge pricing logic and fare calculation service
- Payment service integration — idempotency, retries, failure handling
- API design — REST endpoints for booking, tracking, and cancellation
5) Round 5 — Bar Raiser (BR) Round
Two DSA problems and one LP question. This round had a higher bar — the interviewer dug deeper into thought process and trade-offs.
DSA 1: Maximum Sum BST in Binary Tree
https://leetcode.com/problems/maximum-sum-bst-in-binary-tree/
DSA 2: Reorganize String
https://leetcode.com/problems/reorganize-string/