Two weeks ago, I found the r/selfhosted Reddit thread and the awesome-selfhosted/awesome-selfhosted GitHub repository. The latter lists hundreds (if not thousands) of "free software network services and applications you can host on your own servers." It lists, for instance, the Ghost content management system under blogging platforms.
The list deserves careful study as there are free alternatives to common apps and services. If you're a developer, you could find utilities you wanted to build are already there and instead of starting from scratch you can learn from and build on top of them.
I liked seeing that many back-end services are being built in Go. Other frameworks and languages include JavaScript (mainly Node.js), PHP, Ruby, and Docker.