How to reduce response time?

Question

PHP

Hello.
The server receives many requests and each of them must be answered with the least delay.
The problem is that you first need to check the incoming data, process it in different ways, generate a response, in some cases perform a couple more additional actions, and all this, of course, affects the speed of the response.
How to "distribute" tasks so that they run with the least delay?
What should be used in this case?

Answer 1

First, do some profiling and see where you have the longest running piece of code.

Answer 2

Caching?

Answer 3

Here is a bunch of potentially useful information
https://ruhighload.com/post/%D0%A7%D1%82%D0%BE%20%...