Struggling with cPanel optimization for our SaaS, any tips?

hey guys, just launched our new SaaS, 'Website Maintenance & cPanel Management Services', and things are picking up faster than we thought! which is great, but also kinda stressing our servers. we're seeing some growing pains, especially with keeping things smooth and reliable.

even though we offer cPanel management services ourselves, internally we're hitting some snags. we're getting these unexpected resource spikes, especially during peak hours, and then everything slows down. sometimes even database connection errors pop up. it's a real headache trying to maintain good service reliability for our users when our own stuff is struggling.

we've tried a bunch of things, you know, the usual cPanel tweaks. optimizing our databases, messing with PHP versions (tried 7.4, then 8.0, now 8.1), put some basic caching in place. spent hours digging through access logs too, looking for problematic requests or bots.

but it feels like we're just patching things up. we're still seeing these pesky errors in the logs. for example, yesterday during a small traffic surge, we got this:

[12-Dec-2023 14:30:01 UTC] PHP Fatal error: Maximum execution time of 30 seconds exceeded in /home/user/public_html/wp-includes/class-wp-query.php on line 2345

stuff like that keeps popping up, and it's always at the worst times. makes me worry about our overall service reliability.

so, i'm wondering, for those of you running a growing SaaS, what are your go-to advanced cPanel optimization strategies? are there specific tools you swear by for monitoring or proactive adjustments? or maybe some best practices for managing server resources to ensure solid site reliability as traffic grows? we really need to move beyond just basic tweaks.

any advice or pointers would be super appreciated. help a brother out please...