I'm going to ask a question about a web application, in detail how to arrange the objects on the page so the application is well usable on most devices and appears nice and practical to end users.
I went straight to Web Applications, but I discovered you cannot post questions about the development of a web application. They suggests to use Stack Overflow for this topic, but they will close and downvote my question is a femtosecond claiming it is opinion-based.
I was looking for a "user-experience" site but I found nothing relevant. There are similar questions here (for example this one or this other) about where to post.
So I'm indeed asking an advice for my specific case, but in general I wonder if there is a way to find out which site would accept a question. Like the engine that shows similar questions while you're typing, is there something that searches among all the SE sites in order to find out questions with similar phrasing, or better looks directly inside the on/off-topic page?
