devtrackers.gg
Pretty well known that Last Epoch began as a passion project here on reddit. This is (pretty much) the earliest post discussing what would eventually become Last Epoch: https://www.reddit.com/r/gamedev/comments/6bxo00/help_designdecide_the_perfect_arpg_diablo_poe/
There were a couple of exploratory polls posted prior to this one but this is the first time the core mechanics really started to get explored and it's cool to look through some of that old history
Couple months later, this post is what caught my attention: https://www.reddit.com/r/diablo2/comments/6qr9mk/creating_a_arpg_skill_system_planning/
It's been a journey of a lifetime for sure =)
I'll do another AMA at some point so people can ask questions on how we (hopefully) pulled this off!