Bek
Tuning of PHP and MySQL depends on your hardware setup. It wouldn't be applicable from one system to the next.
We had, for instance, 30 PHP-FPM children on a 6 core hyperthreaded xeon. I found 2.5 processes per thread to be optimal. How this translates to a single vcore vps? It probably doesn't. The server also had 36GB of ram, so we could have a very large shared cache with MySQL. I even tuned Opcache to use up to 1GB, though it never reached over ~400MB.
