hzrd149 slide 
https://blossom.us-ord-1.linodeobjects.com/62ebe1c3163b5a3291c3567a6d4f0ed1d00d9d8fb4507c303272a1ec8707729a.pdf

slide workshops Casa21 https://vstabile.github.io/workshop-nostr-design-patterns/

Uncle bob video https://www.youtube.com/watch?v=ssNkOMx2E5Y