tl;dr:Another guide to OAuth 2.0? Well yes. And no. FusionAuth's Modern Guide to OAuth distills hundreds of conversations about OAuth's eight modes, workflows, and grant types, and then offers advice on choosing the best OAuth mode for your scenario.
tl;dr:"Focus on the intent of the change, not the mechanics. Why was this change needed? What drove it? What would you want to know about this reasoning or decision a year from now? What would you want a new team member approaching this code base to know?"
tl;dr:Users don't care about "elegance of code or "how much you love to develop." They are "just trying to finish a task and get on with their life," developing empathy for their experience is important.