On Autosave In Desktop Apps

I’m generally not a fan of desktop apps with autosave, where the app will save your changes automatically, as opposed to committing them to disk when you press Cmd+S. But there are a few exceptions, like Obsidian. That has autosave that I don’t think twice about which, when considering that the best features are usually the invisible ones, credits it as autosave done well. And I wonder why this works. I think it comes down to a very deep undo stack and it being an app that I keep open all week. It also doesn’t rely on the file system paradigm. Yes it uses the file system, but that’s not exposed to the user while using the app. It doesn’t feel like you’re opening Markdown files to edit, despite the fact that you actually are opening Markdown files to edit.

Compare that to something like MacOS Preview, with an autosave that annoys the crap out of me (and has resulted in data loss more than once). I launch it from the Finder and it’s usually opened for a few minutes at most. It’s an app that’s frequently closed, loosing any undo changes that I probably wanted to keep. Maybe it does versioning? But that’s a concept that goes beyond the file-based approach I understand, so recognition of those features is completely lost on me.

So, maybe good desktop autosave is possible if the app is expected to be a) open for a long time, b) has a very deep undo stack, and c) abstracts the file system. If the user needs to think of files, do not use autosave.