[dllthomas]

"[I]t would seem conceptually possible to catch them through a strongly typed language and framework that abstracts all the underlying technologies and compiles to a combination of backend executable(s), and front-end HTML, JS, and CSS, and includes all the routing for both ends"

That would certainly do it, but I think all you need is some definition of interface that you can check your code against on both sides. This could be generated by one side and consumed by the other, or produced directly by the programmer(s) and consumed by both. You would need some means of actually checking your code against the specification on the consuming side(s), but they needn't be part of some broader framework (beyond the trivial sense in which they already are).

[dragonwriter]

Sure, you can do that; but the problem is that you then have to worry about type system mismatches between the interface definition language, and the back- and front-end application languages.

There have been lots of things that do something like this: SOAP and the associated WS-* standards are probably the best known.

[dllthomas]

Very true, and certainly still a big undertaking, depending a little on how well the type systems at either end line up.