[tdeck]

There are still some interesting pitfalls though. A friend of mine vibe coded a small browser based app to track something personal over a long time period. Eventually he plans to share the app with others. It worked, but I was curious where it stored the data and he didn't know.

It turned out it was using LocalStorage, which is not entirely unreasonable, but there are obvious drawbacks (e.g if you move the file it might become inaccessible, if you switch machines there's no convenient way to transfer the data, there are all kinds of ways to lose it, etc..).

In this case "how is this storing my data" is a fundamental question with plenty of implications for your app over its lifetime, but most non-computer people don't think to ask it at all. These days many users enter CS programs without knowing how to manage files and folders on their computer, because even that is often abstracted away.