I bought a Mac mini a couple years ago to develop an app and went with the cheapest model: $600 for 256GB version. Once I had Xcode, Visual Studio, and the rest of my development setup installed, I was down to roughly 60GB free. After every build, I moved installation + build/debug files to an external drive to save about 1GB.
Over the following year, roughly 20 releases later, my disk was full. Xcode generates a ton of hidden cruft in the DerivedData folder during every build/release that I wasn't even aware of! I spent a couple days googling and trying free & paid disk space analyzers (sidenote: I didn't realize how good we have it in Windows-land, there are so many good free tools but in Apple-land they are all so frustrating to use and most of them are totally useless for this particular case). Eventually, I found an Apple forum thread explaining where Xcode hides its generated build data, it was like 8GB of stuff per build! I set a calendar reminder for every 12 months to clean this folder.
I can't move anything else to an external drive really because what's left is necessary for build environment. I don't use the Mac for anything except development, so I've literally removed everything and it's down to barebones but it's still a struggle. If I had known I would have invested another $150 for the 512GB version.
Over the following year, roughly 20 releases later, my disk was full. Xcode generates a ton of hidden cruft in the DerivedData folder during every build/release that I wasn't even aware of! I spent a couple days googling and trying free & paid disk space analyzers (sidenote: I didn't realize how good we have it in Windows-land, there are so many good free tools but in Apple-land they are all so frustrating to use and most of them are totally useless for this particular case). Eventually, I found an Apple forum thread explaining where Xcode hides its generated build data, it was like 8GB of stuff per build! I set a calendar reminder for every 12 months to clean this folder.
I can't move anything else to an external drive really because what's left is necessary for build environment. I don't use the Mac for anything except development, so I've literally removed everything and it's down to barebones but it's still a struggle. If I had known I would have invested another $150 for the 512GB version.