Rate Limiting Explained: Why We Need It + Fixed Window Algorithm

Too many requests can bring down a perfectly healthy backend. In this video, we start our new Rate Limiting series from the basics and understand why rate limiting is needed in real-world backend systems. We'll start with a simple problem: what happens when one client sends too many requests to our server? Then we'll learn: • What is Rate Limiting? • Why do we need Rate Limiting? • How does a Rate Limiter identify a client? • User ID vs API Key vs IP Address • What is a Rate Limit Key? • How does request counting work? • What is Fixed Window Rate Limiting? • How does the Fixed Window algorithm work? • How does the request counter work? • Fixed Window example • The Boundary Problem in Fixed Window At the end, we'll see why Fixed Window is simple but has an important limitation — and that naturally leads us to the next video, where we'll explore Sliding Window Rate Limiting. This series will gradually move from the basic Rate Limiting concepts to Distributed Rate Limiting and Redis-based Rate Limiting. If you're learning Backend Development, System Design, APIs, Distributed Systems, or preparing for System Design interviews, this series will help you build the concepts step by step. Don't forget to Like, Share, and Subscribe. Your support gives me a lot of motivation to keep creating videos and make difficult technology Easy Actually. #RateLimiting #SystemDesign #BackendDevelopment #FixedWindow #DistributedSystems #backend #caching #redis #systemdesign #softwareengineering #backenddevelopment #easyactually #database #techexplained