[soneca]

I think this happens because the term "side-project" has a lot of possible interpretations:

- Hobby project to play with some tech just because you find interesting

- Hobby project to play with some tech that might help your career in the future

- Homework project to learn about the tech you currently use at work

- For-profit project to hopefully earn some extra money

- For-profit project to hopefully earn enough money to allow you to quit your day job (my case now)

- Portfolio-making projects to show at job-interviews as a junior developer (my case a couple of years ago)

All of them seems legit if your decision to do them is personal. But some of them might be prone to abuse by employers

[C1sc0cat]

No I would have taken side project or gig - to absolutely mean a moneymaking enterprise.