Please help I could not find a drawing tool that was submitted to HN

Hi guys.

A few months ago, I found a very interesting link on HackerNews which feature a cool drawing tool that can visualize the architect of "normal" web applications. I can vaguely remember these features:

- Can be drag-and-drop-ed

- Written in React?

- Interactive: put a frontend somewhere, a backend somewhere, and a database in anywhere else, and you can push a button to look at data/dots that go from frontend to backend, and from backend to database

I have been looked around for nearly two hours at my bookmarks, my history, and even on HackerNews's Algolia, but I could find nothing. Can someone please help me with the finding?

Thanks a lot!

EDIT: improve the format