Metaprogramming: An Introduction to JavaScript (ES6) Proxy

You're quite correct. My team just inherited a large node codebase that had proxy sprinkled everywhere, complete with a custom undocumented dsl written using proxies. It was a nightmare to learn, hard to extend without breaking and resulted in quite a few refactoring sessions.

I think proxies have their place, but most apps don't need them imo

I've been using Immer which relies on proxies to give you a plain object interface but also copy on write immutability.

It's very nice and I think is a practical example of when proxies make sense. However it does at times suffer from the cost of doing magic: you handle them in unusual ways and suddenly they break a lot.

If I understood correctly, The Reflection part of the Metaprogramming can be broken further into multiple parts like, - Introspection: Code is able to inspect itself - Self-Modification - Intercession: Acting behalf of somebody else

To me, Proxy is more into the category of 'Intercession', isn't it?

Proxies trace back their origin in mirrors/mirages in metaprogramming for OO languages. (shoutout to AmbientTalk) It's a very Smalltalk way of doing reflection and intersection.

Do you mean that it lacks syntactic abstractions to be called metaprogramming?