1. What It Is
Rate limiting controls how many requests a client can make to your API within a time window. Throttling is closely related — it reduces the rate of requests rather than hard-blocking them.
The problem it solves: Without rate limiting, a single misbehaving client (or an attacker) can overwhelm your backend, cause resource exhaustion, drive up your infrastructure costs, or degrade service for all other users. Rate limiting protects availability and fairness.
Why you should care: Rate limiting is standard in every production API. It's part of API hardening, a tool against brute-force attacks (e.g., login endpoints), protection from accidental runaway clients (a bug in a cron job hitting your API in a tight loop), and a mechanism for tiered pricing models (free tier: 100 req/min, paid tier: 10,000 req/min).
2. How It Works in Practice
Common Algorithms
Fixed Window Counter Count requests in fixed time buckets (e.g., 100 requests per…
In the full tutorial
- 3. Common Real-World Usage
- 4. Trade-offs and Common Mistakes
- 5. Interview Angle
- 6. Practical Examples