2026-05-19 · Express.js

Add rate limiting to an Express API

Pick a window strategy, key requests by user, and return 429s clients can actually handle.

Introduction

From installing a store to configuring proxies and Redis-backed limits, with sample responses and a stress-test check.

What usually goes wrong

Teams that skip this step tend to share three failure modes:

  • Optimizing a number nobody agreed to move.
  • Copying a setup from a project with different constraints.
  • Deferring the decision until it is expensive to reverse.

How to approach it

  1. State the problem in one sentence, in the words your users would use.
  2. Pick a signal you can measure weekly, not just at launch.
  3. Timebox a small trial; a two-day spike beats a two-week debate.

Wrap-up

If Express.js taught us anything, it is that boring consistency beats clever one-offs. Bring the lessons back to your team before they fossilize into folklore.