LeetCode is a system that has a collection of programming language questions. For each question, users can write, compile, run, and submit code which runs through a bunch of test cases. User-submitted code must be stored in a database. Every week, there is a contest where people from around the world participate, with a live leaderboard displayed during the contest. Users are ranked based on accuracy, time, and speed.

Functional Requirement

• Problem Management
• Submit Code
• Live Coding Contest

Non Functional Requirement

• High availability
• High Scalability
• Low latency
• Security

API Endpoints

Problem Management

GET  /api/v1/problems
GET  /api/v1/problems/{problemId}

Submit Code

POST /api/v1/submissions   # {problemId, code, language}
GET  /api/v1/submissions/{submissionId}  # Result

Live Contest