In all honesty, these optimizations are quite basic. We already used MariaDB instead of MySQL itself. Other things listed in the post are something that we have standard across all our databases, well, except for deleting the data to speed up the database.

Have you also considered Percona MySQL server? I think they say they have the best performance (but I haven't tested their implementation yet).

No, unfortunately our company’s and external regulatory compliance policies require us to host all data within the country itself, alongside it being required to be run on an infrastructure that is easily auditable. So as a policy within the company, all our internal services are open source and self hosted.