I like to understand the whole chain - from writing code to actually run the application and make it available to the world. Therefor I am using my own server for my own projects, instead of services. As OS I use Ubuntu, my HTTP server of choice is Nginx. I also understand the common security-pitfalls and try to avoid them with a hardened setup, such as using a firewall.
My first Git repository dates back to 2009, so I've been using version-control basically forever. Nowadays I like to use git-flow along with it. Besides Git, I do test-driven-development with Mocha.js (now learning Jest) for years. Other than that, DevOps is a pretty new field for me. But I am digging it. For example: this website is auto-deployed with a server that is listening to GitHub webhooks, and restarted with PM2.