One fun use case is that you can use proxies to detect accesses to nonexistent properties of JS objects, and you can then throw or log a warning rather than hav

One fun use case is that you can use proxies to detect accesses to nonexistent properties of JS objects, and you can then throw or log a warning rather than having them just return undefined. Unclear if you'd want to do that everywhere (due to perf reasons), but might might be a good thing in development/tests. You can also use proxies to aid in code migrations. For example, let's say you want to migrate your frontend code from `user.id` to `user.handle` and eventually stop returning `id` from the backend. If you wrap server responses in a proxy, then you can warn in production if any code ever accesses `.id`. That's a lot more comforting than trying to search the code, and even in a 100% TypeScript codebase you still might have some dynamic accesses that the proxy would catch. (I haven't actually done either of the two above approaches in a real-world scenario, but they've always seemed appealing, and I'm curious of others have real-world experience with them.)