How to reset Linux on cloud

Sorry if it is too lame to ask this question, i actually have a way that i flush things manually:

sudo deluser --remove-home unwanted_user
sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get autoremove --purge -y
sudo rm -rf /etc/custom_config /var/log/*

But somehow i thing there should be a batter way!

Assume deleting VM/Machine and re-creating is not an option.