The portfolio argument is real, but it's not even the best reason. Open source teaches you something no lecture or tutorial can: how professional software is actually written.
Beyond the Portfolio Argument
Yes, open source contributions improve your CV. But that framing undersells the real benefit. The thing you can't get from tutorials, courses, or even university projects is exposure to code written by professionals at scale over years — the kind of code that has survived edge cases you haven't imagined yet.
Reading a mature open source codebase is like doing a reading comprehension exercise where the answer key is the git history. Why is this abstracted? Because it wasn't always. Why is there a comment saying 'do not change this'? Because someone changed it and broke production in 2019. That context is priceless.
What You Actually Learn
Code review. Not the kind where your lecturer says 'good work', but the kind where a maintainer explains why your naming is confusing, why your abstraction leaks, and why the approach you thought was clever is actually a known anti-pattern. It stings the first time. It makes you permanently better.
You also learn how distributed teams collaborate: async communication, descriptive commit messages, issues as long-form technical discussions. These are skills that the classroom cannot teach because they require a real asynchronous team.
Just Start — The Bar is Lower Than You Think
The most common reason students don't contribute is the belief that their code isn't good enough. It isn't yet — and that's fine. Nobody's first PR is impressive. The bar for a first contribution is: does it solve a documented problem without breaking anything else? That's it.
Start with documentation fixes. They don't require understanding the whole codebase, they're always needed, and maintainers are often more grateful for them than for code contributions. A clear explanation of a confusing API can help thousands of developers. Your first PR doesn't have to be heroic.
2nd year CS student, open source advocate, and maintainer of two small npm packages.
