Questions
4 of 6
1How would you design a high-availability, horizontally scalable Go backend service?
2How do you build a basic HTTP server using only the standard library?
3How would you implement graceful shutdown for an HTTP server handling long-lived connections?
4How do you implement rate limiting in a Go API — per user, per IP, and globally?
5How would you implement middleware in Go using the standard library pattern vs a framework?
6What are the trade-offs between REST and gRPC for internal Go microservices?
golanggolang
Basics
Data Structures
Interfaces and Types
Concurrency
Memory Management
Error Handling
Packages and Modules
Web and API Development
Databases and Storage
Testing
DevOps and Deployment
Standard Library
04 / 06

How do you implement rate limiting in a Go API — per user, per IP, and globally?

Use the token bucket algorithm from golang.org/x/time/rate for single-instance rate limiting. For distributed rate limiting across multiple instances, use Redis with atomic Lua scripts.

Rate limiting middleware
Rate limiting strategies
  1. 1

    Token bucket (golang.org/x/time/rate): allows bursts up to bucket capacity, refills at a constant rate

  2. 2

    Sliding window: more accurate than fixed window, prevents burst at window boundaries

  3. 3

    Per-user rate limits are more fair than per-IP for authenticated APIs — use user ID from JWT

  4. 4

    Redis-cell (redis module) or Lua scripts for distributed rate limiting across service instances

  5. 5

    Return Retry-After header with 429 responses to help well-behaved clients back off