Six years later, how has antifragility thinking changed? Carl and Richard talk to Barry O'Reilly about his ongoing work on building highly reliable software. Since Barry's last appearance six years ago, he's returned to school and is writing a PhD thesis on antifragility. Studying complexity theory, Barry approaches software architecture with a minimalist view - you only add architecture when you see the application needs it. This leads to ideas around residuality - and a progressive way to build software that yields amazing results!