Online Assessment (OA)
Platform: Amazon’s internal coding portal / Hackerrank
Questions:
Array manipulation (prefix sums or sliding window)
String or hashmap-based problem (e.g. find first unique character)
Debugging question (identify and fix logical errors)
Difficulty: Medium–Hard
Focus Areas: Data Structures (Arrays, Strings, HashMaps), Time Complexity, Edge Cases
Technical Round 1 (Data Structures & Algorithms)
Duration: 60 minutes
Questions Asked:
Implement LRU Cache using LinkedHashMap or custom DLL + HashMap.
Solve “Longest Substring Without Repeating Characters” (Two Pointer / Sliding Window approach).
Follow-up: Discuss time and space complexities.
Additional Discussion:
Code optimization
Handling large input cases and memory efficiency
Technical Round 2 (System Design + Problem Solving)
Duration: 60 minutes
Questions:
Design a URL Shortener / BookMyShow Ticket Booking System (Low-Level Design)
Implement core classes and relationships
Asked about OOP principles, Design Patterns (Singleton, Factory)
Follow-ups:
How would you scale the system?