With any luck, your company has a Chris.¹ Every place I’ve worked at has one.

This is a developer whose intimate knowledge of the codebase takes years to build. This familiarity includes the dusty corners that few venture into — the code that works but has been untouched for eons. The modules whose original authors are long gone, written when the business requirements were completely different, when best practices and conventions were ignored (or more charitably, before they had been established). “Here be dragons.” Every codebase I work on has these areas, and they’re terrifying.

Chris to the rescue. If you have a question about why a class was designed the way it was, he knows the answer. During code reviews his insight is indispensable. With extra context on his side, he highlights flaws and unintended consequences that others miss. He’s a librarian and historian of the codebase, with a detailed mental map of the system that is impossible to replicate in a wiki alone.

The jury is out on whether 10x programmers exist, but with his ability to unblock others and make them more productive, Chris comes close.

If your company doesn’t have a Chris, you should get one.² Better yet, get two.