Contributing to open source is terrifying until it isn't. Here's the exact process I used, the mistakes I made, and why every engineer should do it at least once.
My first PR to an open-source project sat open for 6 weeks before being politely closed. The maintainer's feedback was direct: I'd solved a problem they'd already solved differently, and I hadn't read the contributing guide carefully enough.
My second PR merged in 3 days. The difference was preparation: I spent a week reading issues, understanding the codebase, and having a conversation with maintainers before writing a single line of code.
The process that now works for me: (1) Find a project I actually use. This ensures I understand the domain and have a genuine stake in improving it. (2) Read every open issue. Look for "good first issue" tags, but also for issues where the maintainer has described the desired solution but nobody has implemented it yet. (3) Open an issue or comment before starting work. Ask if the approach you're planning makes sense. Maintainers appreciate this — it prevents wasted effort on both sides. (4) Match the project's code style obsessively. Not your preferred style — theirs. Read three or four existing files before writing anything. (5) Write a clear PR description explaining what changed, why, and how to test it.
The career benefits are real. Three of my open source contributions have come up in job interviews. One led directly to a contract. But the more lasting benefit is the exposure to codebases built by engineers far more experienced than me. Every merged PR is a free mentorship session.