I am a hobby programmer contributing to software I personally use.
My primary goal is to understand how software actually works. For me, reading source code is the most direct and reliable way to see what a program does, how it behaves under different conditions, and where its limitations are. Documentation and external behavior only describe a system from the outside; the implementation itself is the ground truth.
I contribute both to deepen that understanding and to give something back. Much of the software I use has proven reliable over time, and contributing fixes or features - including those requested in issues - is a straightforward way to support projects that others depend on as well.
Most of my work focuses on terminal-based applications, Unix userland tools, shells, and other text-based interfaces, typically in long-lived C codebases.