My heuristics are wrong. What now?

Experienced tech leaders and principal engineers are facing a career-defining challenge: many of the heuristics they've built over decades are no longer valid in the age of AI-assisted development. The author argues that the right response is not to discard all experience, but to actively rebuild and validate rules of thumb by getting hands-on with new tools, building real things, and approaching the current shift with humility and curiosity. Those who combine deep experience with a willingness to update their mental models will be the most valuable engineers; those who refuse to adapt will become liabilities.