Ikhlaque Ahmed Maner’s Post

🚦 LLD Case Study: Designing a Rate Limiter in Node.js Rate Limiter is a very common Low-Level Design (LLD) interview question for backend roles. Instead of explaining it only in theory, I decided to design and implement it end-to-end with a production mindset. 🔗 GitHub: https://lnkd.in/drD79sfY What this project covers (LLD-focused) • Token Bucket, Fixed Window, and Sliding Window algorithms • Strategy Pattern to switch algorithms without changing client code • Redis + Lua scripts for atomic operations • Express middleware–based design • RFC-style rate-limit headers • Handling real-world scenarios like burst traffic and concurrency Why I built this In interviews, the expectation is not just: “Do you know the algorithm?” But also: • Can you structure clean, maintainable classes? • Can you extend the design without breaking existing code? • Can you handle race conditions? • Can you think about failure scenarios? This project answers those questions with actual working code, not just diagrams. Key design takeaway Algorithms change. Good design should not. Using the Strategy Pattern, each rate-limiting algorithm is isolated, testable, and replaceable without touching the rest of the system. If you’re preparing for backend LLD interviews or working on API design, this might be useful. Feedback and discussions are welcome 🙂 #LowLevelDesign #SystemDesign #NodeJS #BackendEngineering #Redis #InterviewPrep #OpenSource

To view or add a comment, sign in

Explore content categories