Deployments can feel slow because we are using deployer. Deployer creates releases on each deploy and copies all the files. This is required in case of production environments to have an easy way to rollback and ensure all files are from a fresh WordPress install and none of them have been edited or corrupted.

But, for non-production environments, we can significantly improve the speed of deployment by simply copying the files using rsync(which will only copy newer files).

TL;DR

Production(master) - deployer
Non-production - rsync