API Rate Limiter Design: Building Scalable Request Control Systems

High traffic spikes and malicious API abuse can quickly bring down even the most robust web services. Implementing a reliable rate limiter is essential for maintaining system availability, protecting resources, and ensuring fair usage across all users. This text-based course guides you through the core concepts of rate limiting, from basic single-server approaches to highly scalable, distributed architectures. You will learn how to select the right algorithms and design systems that handle millions of requests with minimal latency. What you'll learn: Understand the foundational concepts of rate limiting and why it is critical for API security and performance; Compare key rate-limiting algorithms, including Token Bucket, Leaky Bucket, Fixed Window, and Sliding Window; Design distributed rate limiters using modern caching technologies like Redis to handle high-throughput traffic; Address critical edge cases such as race conditions, multi-tier rate limiting, and client-side handling of rate limits; Apply best practices for monitoring, logging, and configuring rate limiters in production environments. You will start with the fundamental terminology and basic mechanisms of request control before moving step-by-step into advanced multi-server setups and real-world architectural design. The written explanations and practical design exercises ensure you can confidently implement these patterns in your own systems. This course is designed for software engineers, system designers, and backend developers who want to understand API architecture. No prior experience with system design is required, though a basic understanding of web development and APIs is helpful. Start reading today to build resilient APIs that stand up to any traffic load.