- Do less IO. (Fewer, smaller HTTP reqs. But mostly just fewer.)
- Do slow operations in ways that don’t block user interaction. (Aka “async” or “cheating”.)
- Write smaller programs. Cut unnecessary features. Most software latency and bugs come from code, so use less of that.
- Profile before you optimize, or go blind from pointless bit twiddling masturbation.
- Profile your actual app with actual data. Microbenchmarks are often inapplicable.
- Write code that you can read and understand.
- Don’t believe anything you read on the internet about speeding up your site until you have verified it for yourself, in the context of your app.