The fact that it's in a single file implies this. I don't think anyone would think they are trying to claim they can replace all of Twitter's production code with this single file.
I don’t think that either. But someone HN made a very spirited argument a few years ago that he could build and run Twitter in no more than 4 servers.
Do you have a link to that comment? I really want to read it. That sounds like a HN classic.
Depends on the servers...
I guess in theory that's true, but not any commercially available server I'm aware of.
I don't think that's true. You could make an effort to show that you'd solved some of the more well-known technical problems, e.g., different messaging architecture to handle users with millions of async subscribers. As it stands this title need not mention Twitter at all. I'm trying to be helpful. If you make the assumption that it's just a simple clone that makes the title even less interesting. The target audience for this post will likely just skip over it.