I know you mean this is as joke, but oddly enough, Pitfall, by Activision is still available!

Not sure, but the blast radius is tremendous, even games from the Atari 2600, a console released nearly fifty fucking years ago have been taken down.

Been using it as well. It requires practice, but it does feel like a better typing experience for a mobile device.

While I’m not experienced enough to explain the full development stack of an OS. Let me throw my two cents.

It typically goes by writing changes. If its superficial ones, like modern UI in Windows 11, then all they need to do is relaunch explorer/the app etc. Every time they make a change in the code, they then build and try it out.

If its a more internal change, deep into the OS. Typically written in C or another low level language. Then its easier to test the changes in a virtual machine, you write your code, compile, build. And then load it up in the virtual machine to see if the OS doesn’t crash and burn.

Later, after it gets past quality control in the company, (but most often these versions sit in beta for a while to catch problems). It then gets put into the Update servers and rolled out in bulk for mass destribution.

Do note, updates don’t need to include the entire OS. Just packages including the file changes as well as general update busywork.

PS: If anyone replies, feel free to correct me. Details may be sketchy but this is the short of it.