To be fair this was after the initial screener interview and I did have a couple of hours to get it done. And we're not talking all the features (certainly not of phpBB) or anything.

3 Tables "posts", "replies", "users" (replies was a closure table), topics index, topic view page, a form page for registration and one for the profile page. JS form validation and a simple layout via CSS and HTML5.

It was more of a Twitter-lite (a very poor man's Twitter-lite)