Reverse Proxies and You: What They Are, Why They Matter, and How Vercel Fits In
May 7, 2025
TL;DR
- Reverse proxies act as intermediaries between clients and backend services, improving performance, security, scalability, and maintainability.
- Platforms like Vercel offer built-in edge features (like global routing, edge functions, and WAF) but don’t fully replace the flexibility and control of a dedicated reverse proxy.
- For modern apps, the real power comes when you combine Vercel’s edge with a smart reverse proxy setup — balancing speed, security, and architectural control.
What is a reverse proxy?
If you made it past the title without your eyes glazing over at the words reverse proxy — congratulations, you’re already ahead of most people (and probably have slightly more patience than a caffeinated squirrel). So, what is this thing, and why should you, an intrepid developer, care?
In the simplest terms, a reverse proxy is a server that stands between the outside world (clients like your browser) and one or more backend services (the apps and databases that actually do the heavy lifting). Instead of your browser awkwardly walking up and asking the backend server for something directly, it goes through the reverse proxy — which acts like a smooth-talking front desk receptionist, deciding how and where to forward your request.
Here’s a taste of what a reverse proxy might do when you visit a site:
- Validate you as a real human: Think CAPTCHAs, Cloudflare’s “Checking your browser” spinny screen, or rate limits to block bots and DDoS attacks (aka the robot hordes knocking at the door).
- Route you to the right backend server: Maybe the server geographically closest to you (for faster responses), or the one with the most free capacity, or — let’s be honest — the one that’s not currently on fire.
- Handle SSL termination: Your browser speaks HTTPS, but the backend may just want plain HTTP. The reverse proxy handles that translation smoothly, like a multilingual middleman.
- Cache static content: Why bother the backend every time someone requests the same image or script? The proxy can serve cached versions and save everyone a lot of redundant work (and server tears).
Why Do People Use a Reverse Proxy?
Earlier, I touched on some of the ways reverse proxies work, but let’s really hammer home why this is such an important (and often invisible) part of many modern tech stacks. I’ll break it down into four big reasons — and no, “because it’s cool” is not one of them.
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Performance:
- Load Balancing: Instead of dumping all incoming requests onto a single backend server and hoping for the best, the proxy distributes traffic across multiple servers. This keeps things fast and smooth for users — and prevents servers from collapsing in exhaustion when your site suddenly goes viral because someone posted it on Hacker News (or, more realistically, Reddit).
- Caching: Why force a server in Las Vegas to handle every request from Thailand when the same content could be served from a nearby server in Japan? By caching frequently requested data closer to the user, reverse proxies cut down the distance data has to travel, making everything zippier.
- Compression: A reverse proxy can compress outbound data before it’s sent to the user, shrinking file sizes and making pages load faster — like zipping up a big file before emailing it, but with fewer awkward attachments.
- Connection Reuse: Instead of opening a fresh connection to the backend for every single request (which is like starting a new conversation every time you want to say something), the proxy can reuse existing ones, saving time and server resources.
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Security:
A reverse proxy acts like a bodyguard for your backend, making sure outsiders only see the public-facing layer. This gives you:
- DDoS protection by absorbing or filtering traffic spikes before they hit your precious backend.
- Anonymity for internal architecture — users only see the proxy, not what’s lurking behind it.
- Centralized TLS/SSL termination so backend servers don’t have to waste brainpower (or CPU) dealing with encryption.
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Scalability & Flexibility:
As your app grows, a reverse proxy helps you:
- Add or remove backend servers without disrupting traffic (because “just wing it” isn’t a scaling strategy).
- Roll out updates gradually (blue-green deployments) or test new features on a subset of users (A/B testing) without breaking everything.
- Seamlessly integrate with third-party services or microservices, without making the client juggle the complexity.
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Maintainability:
A reverse proxy can centralize logs and metrics, giving you a bird’s-eye view of your system health — like having a dashboard instead of checking each server manually. Plus, it helps apply consistent error handling, rate limits, and auth rules across services, simplifying troubleshooting when things inevitably go sideways.
Reverse Proxies vs. Vercel’s Analytics, Edge Functions, and WAF
As a longtime fan of Vercel, I initially approached this topic half-expecting to declare that platforms like Vercel have made traditional reverse proxies obsolete. After all, Vercel offers a slick all-in-one package: built-in web analytics, performance insights, edge functions, and a web application firewall (WAF), all served on top of a lightning-fast global edge network. Why would you bother setting up your own reverse proxy when Vercel basically hands you the future on a silver platter?
But here’s the thing I learned: the relationship between reverse proxies and platforms like Vercel isn’t competitive — it’s symbiotic.
Vercel’s Edge Strengths
Vercel’s edge network distributes your app across globally deployed servers, meaning that when a user in Tokyo requests your site, they’re served from a node close to them, not from some lonely origin server in the U.S. This brings:
- Low latency thanks to geographic proximity.
- High availability because traffic can be rerouted if one edge node goes down.
- Seamless scaling as Vercel handles the heavy lifting of traffic spikes and CDN-level distribution.
Plus, with Edge Functions, you can run lightweight code at the edge itself — personalizing content, handling geolocation logic, or preprocessing requests before they even touch your backend. And the built-in WAF (Web Application Firewall) means a lot of common security protections are handled out of the box.
Where Reverse Proxies Still Matter
So, why do reverse proxies still have a role here?
- Custom Routing: If you need to route traffic between multiple complex backends, integrate with legacy systems, or mix cloud providers, a dedicated reverse proxy gives you more granular control than Vercel’s standard routing.
- Advanced Load Balancing: Vercel balances traffic across its edge, but if you manage private infrastructure or hybrid setups (on-prem + cloud), you might need a reverse proxy to intelligently distribute traffic behind the edge.
- Specialized Security & Compliance: Enterprises may have unique WAF rules, custom auth flows, or regulatory needs that require more than what Vercel’s default protections provide.
- Layered Architecture: Sometimes you want both — Vercel’s edge + your own reverse proxy layer — to handle things like API gateway logic, rate limiting, or multitenant routing across internal services.
Example: Combining Vercel + Reverse Proxies
Let’s say you’re building a SaaS platform. Your public-facing app is served beautifully from Vercel’s edge, ensuring fast page loads worldwide. But under the hood, you have an internal API service running on Kubernetes, a legacy payments service living in a dusty corner of AWS, and a private admin dashboard hosted elsewhere. A reverse proxy (like NGINX, Traefik, or even a custom one in Rust) can sit between Vercel and your backends, routing requests smartly and securely to the right internal resources — all while Vercel handles the flashy public layer.
So no, Vercel hasn’t killed off the reverse proxy. It’s just shifted where and how we apply this tool. The future isn’t “edge vs. proxy” — it’s edge + proxy, working together like a weird, beautiful, distributed sandwich.
In Conclusion
Reverse proxies may not be the flashiest piece of tech in your stack, but they’re the silent workhorses keeping modern web applications fast, secure, and scalable. While platforms like Vercel offer impressive edge capabilities that abstract away much of the complexity for developers, they don’t eliminate the need for proxies — they simply change the way we use them.
By understanding how reverse proxies and edge platforms complement each other, you can design smarter, more resilient systems that take full advantage of distributed networks, specialized backends, and advanced routing needs. Whether you’re building a small app or managing a sprawling SaaS empire, knowing when and how to layer these tools can give you the performance edge (pun absolutely intended) you need.
Cool resources and projects to check out
Going Further: Cool Projects to Explore
If you’re intrigued by the world of reverse proxies and want to go beyond theory, here are some great projects, tools, and resources to deepen your understanding:
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NGINX: The classic, battle-tested reverse proxy and web server. Try setting up a simple NGINX reverse proxy for a small project and experiment with load balancing, caching, or SSL termination. (Pro tip: break something on purpose, then fix it — that’s where the real learning happens.)
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Caddy: A newer, developer-friendly reverse proxy that automatically handles HTTPS with zero config. Great for personal projects or small deployments where you don’t want to wrestle with certs.
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Traefik: Built with dynamic environments in mind (think Docker, Kubernetes, microservices), Traefik shines when you need flexible, automated routing and real-time configuration.
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Envoy: An advanced proxy often used in service mesh architectures. If you want to play with next-level traffic control, observability, and resilience patterns, Envoy is your playground.
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Awesome Reverse Proxy (GitHub): A curated list of reverse proxy tools, guides, and resources — because who doesn’t love an “awesome list”?
Curious how the magic works under the hood? Stick around — my next post will walk you through building a reverse proxy in Rust (because why not impress your friends and torture yourself at the same time).