Building a CI/CD Pipeline Runner from Scratch in Python (opens in new tab)

Jenkins, like many tools with extreme flexibility, sucks as much as you make it suck. You can pretty easily turn Jenkins into a monstrosity that makes everyone afraid to ever try to update it. On the other hand, you can also have a pretty solid setup that is easy to work on. The trouble is that the tool itself doesn't guide you much to the good path, so unless you've seen a pleasant Jenkins instance before you're likely to have a worse time than necessary.

Since you're exercising, you can take it to the next level where you don't specify the next step but the inputs to each task, allowing you to infer the DAG and implement caching...

Docker is unusable for build tools that use namespaces (of which Docker itself is one), unless you use privileged mode and throw away much more security than you'd need to. Docker images are difficult to reproduce with conventional Docker tools, and using a non-reproducible base image for your build environment seems like a rather bad idea.