As presented at the Gearset DevOps Summit on November 2. This version has animations in it, so the diagrams look good, but there are a lot of slides! A version without animations is here https://speakerdeck.com/aidanharding/philosophy-challenges-and-opportunities-of-devops-on-salesforce-no-animation.
In this presentation, we looked at the questions behind DevOps on Salesforce: Why is it hard? What is the real source of truth? What approaches can we take to make progress?
I encourage you to keep things simple and use just enough process/tooling to get what you need.