Cool! Always great to have another Roguelike developer. It's a genre that really helps to focus development effort on gameplay, systems, and imagination.
I have been working on this stuff for decades so I'm not always sure what advice is relevant. But here's a shot at it.
Another thing they do on that sub-reddit is an annual communal working-through of the LibTCOD Roguelike tutorial. Roguelike developers being what they are, people will often work alongside in some new language they want to try. For instance, this one from Lokathor, in Rust. I've learned quite a bit from Lokathor's Haskell attempt from the year before the Rust one.
If YouTube videos are your jam, the annual Roguelike Celebration generates some good ones. I enjoyed Bob Nystrom's talk about how he architects his Roguelike, for instance. I'm still kicking myself for not going to the Roguelike Celebration yet; maybe next year.
Hope this helps!