Yeah, it's kind of funny when you look at what GWT had vs what modern JS development looks like. Multiple browser targets, using the same language on both clie

Yeah, it's kind of funny when you look at what GWT had vs what modern JS development looks like. Multiple browser targets, using the same language on both client and server, static types, RPC declarations, a dev mode server, etc. That said, GWT-RPC also went from being nice to a pain. The serialization formats were "proprietary", in the sense that they were GWT-specific and couldn't be reused with any other platform. There were actually two separate formats. Client->server was some kind of custom text format, while server->client was _technically_ JSON, but the contents were still basically opaque. (I found a document that tried to reverse engineer the format, and it was pretty ugly.) That was another pain point, actually - inspecting API calls in a browser's Network tab was useless, because you couldn't interpret anything out of the contents. Also, I'll take promises (and `async/await`) over GWT's ugly `MyRpcInterface/MyRpcInterfaceAsync` definitions and success/failure handlers any day. When I rebuilt my app, I was lucky enough to be able to re-expose the same internal API endpoint implementations over JSON-RPC. That let me keep my existing backend logic, and build out the new JS client separately while keeping the old one in place until the new one was ready.