What a Hilariously Wrong Time Estimate Taught Me About the Future of Organizations

The Funniest Bug in AI Here's something that made me laugh out loud last week. I asked an LLM to plan the upgrade of a legacy application — Frontend AngularJS 1.8 and Backend Java 11 — to a more modern stack: Angular 21 and Java 21 LTS. A bread-and-butter modernisation task I've seen dozens of times in banking and enterprise projects over the past five years. As any experienced vibe engineer would, I started with a deep analysis: mapping dependencies, creating nested AGENTS.md files throughout the codebase, feeding the LLM the full dependency graph and project structure until it understood the system as well as I did. The resulting migration plan was solid — breaking changes identified, a clear path from each AngularJS controller to standalone Angular components, Java module system accounted for, testing strategy included. Then I asked it to estimate how long this would take. Nine to twelve months , it said. With a dedicated team of three to four engineers. I almost spat out my coffee.