In this video, I’ve explained the Low Level Design (LLD) of a Rate Limiter from scratch. We design a thread-safe and efficient rate limiter that limits requests based on userId and user tier (like free, premium, etc.). 🔍 What’s covered: - Fixed Window, Sliding Window, and Token Bucket algorithms (explained with animations) - Thread Safety and Efficiency in Implementation - UML Diagram and End-to-End Code Explanation - How rate limiting prevents abuse and ensures system stability By the end, you’ll fully understand how Leetcode implements rate limiting in their code submission api. ⏱️ Timestamps 0:00 - Intro 0:10 - Understand the System 5:20 - Requirement Gathering 7:03 - UML Diagram 11:35 - Fixed, Sliding, Token Bucket 18:50 - Code Explanation 28:54 - Output