I think you may have been asking about the steemit.chat dev channel he mentioned. It's not private, but it's also not very active either, easy to find tho if you go to steemit chat and type #dev in the search bar.... you might try https://discord.gg/73KQBgb for a little bit more active devstuff lurking.. although most of it isn't talking about projects, it tends to be question and answer more or less.