Let’s face it – slow APIs are a pain. They frustrate users, kill productivity, and can make your whole app feel sluggish. We’ve spent years optimizing APIs, and in this blog post, we want to share what really works when it comes to speeding things up.
First, though, let’s be real – don’t jump straight into optimization mode. We’ve learned the hard way that premature optimization is usually a waste of time. Start by actually measuring where your bottlenecks are through load testing and request profiling. Once you know what’s actually slow, then you can fix it.
Here are 7 techniques we’ve found that make the biggest difference:
Smart Caching
Caching is your best friend when it comes to API speed. Store those expensive calculations and database queries so you don’t have to repeat them—Redis or Memcached work great for this. Even caching for just a few seconds can make a huge difference.
Connection Pooling
Creating new database connections for every request is slow. Instead, maintain a pool of connections you can reuse. This is especially important in serverless setups, where connection management can become complicated. Tools like AWS RDS Proxy can help here.
Fix Those N+1 Queries
We’ve all been there – you fetch a list of items, then make separate queries for each item’s details. Suddenly, you’re making hundreds of database calls instead of one or two. Use joins or batch your queries instead.
Smart Pagination
Nobody needs 10,000 records at once. Break up large responses into manageable chunks using cursor-based pagination. Your servers and clients will both run smoother.
Fast JSON Processing
JSON parsing can be surprisingly slow at scale. Use high-performance serialization libraries and keep your response objects clean and simple.
Compress Everything
Enable gzip compression (or better yet, Brotli) on your responses. The tiny bit of CPU overhead is worth it for the bandwidth savings.
Async Logging
Don’t let logging slow down your responses. Buffer those logs and write them asynchronously. Just remember there’s a small risk of losing logs if your app crashes.
Conclusion
The key to making all this work is good monitoring. Set up proper metrics and alerts so you know when things slow down. Keep testing under load. Watch how real users experience your API.
Remember – you don’t need to implement everything at once. Start with whatever’s causing your biggest slowdown and work from there. Your users will definitely notice the difference.