API gateways sit at the front door of your backend services. They handle incoming requests and route them to the right place, while taking care of cross-cutting concerns like authentication, rate limiting, and logging so your individual services don’t have to.
Building one from scratch is an incredible way to learn Rust. You’ll work with async networking, trait-based abstractions, concurrent data structures, and real-world patterns that come up in production systems every day.
What We’re Building
Over the course of this series, we’ll build a fully functional API gateway called Ferroway that can:
- Accept incoming HTTP requests and proxy them to backend services
- Match requests to the right upstream service based on path rules
- Run a pipeline of middleware (logging, CORS headers, custom headers)
- Rate limit clients to protect your backend from abuse
- Load balance across multiple instances of the same service with health checks
- Read its configuration from a YAML file and support JWT authentication
Prerequisites
This series is designed to be beginner-friendly. You should have:
- Rust installed on your machine (we’ll be using the latest stable release)
- A basic understanding of what variables, functions, and structs are in Rust
- Some familiarity with the command line
We’ll explain Rust-specific concepts like ownership, borrowing, traits, and async/await as they come up naturally in the code. You don’t need to be a Rust expert to follow along!
Series Outline
Project Setup & Your First HTTP Proxy - We’ll set up the project, learn about Tokio for async Rust, and build a working reverse proxy that forwards requests to a backend server.
Routing & Path Matching - We’ll add a routing layer so our gateway can send requests to different backend services based on the URL path.
Middleware Pipeline - We’ll build a composable middleware system using Rust traits, then implement logging, CORS, and custom header injection.
Rate Limiting - We’ll protect our backend services by implementing a token bucket rate limiter that tracks requests per client IP.
Load Balancing & Health Checks - We’ll distribute traffic across multiple instances of the same service and automatically stop routing to unhealthy backends.
Configuration & Authentication - We’ll move our gateway config into a YAML file and add JWT-based authentication middleware.