What is the best way to change sass ariables with the customizer?

So this is the first time for me developing a WP theme. I would like to add some options in the customiser to change colours. I feel like having everything as an output in a style tag in the header isn’t the most efficient.

Since I’m working with SASS I thought it could be easy to change these variables and have it compile again ~somehow~.

I looked into it but couldn’t really find good resources/instructions. Gulp seems to be mentioned and I’ve played around with the wp-scss plugin (which would make my theme rely on an external plugin – I don’t like that) but I’m really not sure what the best approach to this is. Also, having the theme that writes files isn’t really accepted.

I’d be happy to hear about your experience with this! Thank you!