If you don’t sleep, your mac also shouldn’t.
Appsomnia is a simple top bar application which prevents your mac going to sleep, starting screensaver or dimming the screen when it’s activated.
It stays on your top bar and you can only click on it to activate or deactivate.
You can also right click on the icon to activate it for a limited period of time.
You can also enable/disable notifications in order to be sure when it it’s active or not.