How to Make Slow Code Easier to Optimize

Application feels slow?

Before optimizing it, find out what is slow.

Use profiling, tracing, metrics, or benchmarks to measure where the application spends its time.

You might discover that a request spends:

Validation        4 ms
Business logic   12 ms
Database        680 ms
Serialization     8 ms

Optimizing 12 ms of business logic probably won't fix a 700 ms request.

Measure things like:

Then optimize the part responsible for the problem.

Performance optimization becomes much easier once you know what needs to become faster.