I usually follow installation instructions provided with the extension documentation. Often it's just a composer require command. Other times there are post installation steps like: di compile, setup:upgrade.
I have a pretty slim local development vm, which performs well normally, but for what ever reason, after installing some extensions it crawls[goes extremely slow, uses tons of resources] for a few hours. I imagine it has something to do with rebuilding caches? Is there anyway to speed this up, or at least make it more predictable / consistent? e.g. a cache warmer?
Just realized one of the extensions seems to have disabled cache. I believe that was the reason for the slowness. It was probably in a console message. Recommend more emphasis, impacts performance greatly.
There are many way to slow down the performance.
1. check server response
2. avoid third party extension
Check website in gtmetrix speed test tool and get what takes max time to load.
1. Enable Magento profiler to understand where is the bottleneck ( It will show complete magento code trace of a page ).
2. Use these tools to understand more about the cause of slowness in the frontend of the site.
b. Google Page speed insights ( To understand what Google recommends )
d. sitespeed.io ( open source tool you can install on your system and check the locally hosted sites as well, other tools cannot test your local website )
e. Lighthouse chrome tool ( If you enable developer tools there is a tab called "Audit" it will give more insights towards the page performance )
3. Use full page cache
4. Implement server-level cache like Redis, Memcache etc.,
5. The new recommendation is upgrading your web server to support HTTP/2 it covers some of the bottlenecks of HTTP/1.1. But please make sure that SSL is enabled otherwise your requests will be served through HTTP/1.1 only.
Give Kudos if it helped or Accept it as solution