What automations are taxing on the hub. Best practises

Hi guys. I created this thread for noobs who might just add every automation out there , thinking a few lines of code here and there won't do harm.
However things like updates and constant polling including debugging can greatly affect the speed , even crashing of the hub if I stand under correction..

I am hoping the community chirps in and adds to this . I wanna be as specific as possible but also what re it's limitations and can anyig like a raspi take some of that stress off the hubitat hub.

Lastly what are some great best practises when cleaning up old drivers/apps and speeding the hub

Any suggestions or advice to us noobs would be greatly appreciated.