Mostly organizing my dotfiles across Windows, macOS, Linux and BSD, however, I have really fallen for Ansible. I discovered at work awhile back, but was able to grok how to make and run a playbook, and I've been hooked since. It also finally allowed me to click the difference between Imperative and Declarative programming!

Careful, not all ansible is declarative or idempotent. Lots of foot guns exist, still a valuable tool