I don't have experience with a side project that has customers, but several times I did do a side project for a paying client.
It was one of the most stressful periods of my life. I was picking them up with another programmer, and I completely failed to understand the amount and the quality they would deliver. I solved it by working day and night for a year or two, or so.
I'd say, do try a project that has customers.
Think twice about a project for a client.
Wait, what's the difference between a customer and a client? I'm not a native speaker and always thought the words meant the same thing (they have the same root in my language).
I thought "client" was just the fancier term, therefore you have customers at a book shop and clients at a law firm. Does a hairdresser or tattoo artist have customers or clients?
I'm not a native speaker as well, maybe that causes the problem :D
I meant the following: customers -> group of people who buy or subscribe to your application, preferably via the App Store, Google Play or some other in-between party. Usually no contract involved.
Paying client -> a single person or business that pays you to develop software, probably with a contract that is signed and specifies what you're going to build, on which timeline, etc.
It was one of the most stressful periods of my life. I was picking them up with another programmer, and I completely failed to understand the amount and the quality they would deliver. I solved it by working day and night for a year or two, or so.
I'd say, do try a project that has customers. Think twice about a project for a client.