API Gateway vs Reverse Proxy

Look, I get it. A reverse proxy can do a lot of the things people claim only an API gateway handles. If you use Nginx to balance load, terminate TLS, and cache a few static files, you’re technically doing some gateway work. I’ve spent plenty of time happily running simple proxy setups that worked for years without adding the overhead of a full gateway service.

When is a proxy enough?

If your service architecture is static, you’re fine with a reverse proxy. Here’s a basic Nginx config snippet that gets you pretty far:

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server {
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  listen 80;
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  location /api/v1/ {
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    proxy_pass http://my-backend-service;
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  }
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}

That’s it. It’s fast, it’s reliable, and it’s easy to debug. If you aren’t changing your backend routes every hour or managing multiple teams pushing their own microservices, you don’t need the extra weight. (I’ll admit, sometimes adding an API gateway just because it’s the industry standard is just an exercise in adding pointless complexity.)

So why does the gateway exist?

“But why shouldn’t I just build my own auth and rate-limiting middleware in the proxy?” That’s a fair point. If you enjoy maintaining custom Lua scripts for Nginx or writing your own authentication plugins, be my guest. However, when you hit the point where your frontend team needs to aggregate five different services, handle API keys, and manage complex request transformations, a standard proxy becomes a nightmare.

An API gateway is basically an opinionated layer that handles the “annoying” stuff for you. It’s not just about routing. It’s about providing a central control plane for:

1. Rate limiting per client ID.
2. Request and response transformation.
3. Detailed analytics and monitoring.
4. Centralized authentication (like handling JWT validation before the request hits your service).

Making the call

I usually draw the line at microservices. If your system is a monolith, stick with a reverse proxy. Seriously. It’s easier to reason about, and the performance hit of a full gateway usually isn’t worth the trouble.

If you’re managing a distributed system where multiple services have their own deployment lifecycles, you’re eventually going to want that gateway. (Maybe I’m just getting old, but I really hate debugging custom routing logic buried in a proxy config file.)

Ask yourself: are you actually using the features of a gateway? If you’re just passing traffic through, delete the gateway and save your infrastructure costs. If you find yourself writing code that looks like a gateway, stop fighting it and just adopt a proper one. Does it solve a problem you have right now, or just one you think you might have in two years?