Back in 2015, while preparing for a senior architecture role, I learned that decision making under uncertainty was a core skill to learn. At the time, I interpreted this as: we know what we know, we know what we don’t know, and we must accept some uncertainty while iteratively reducing risk over time. After more than a decade of architectural work, I realize I missed a crucial aspect: uncertainty isn’t only about manageable risks — it also encompasses events that can turn the entire system upside down.