Jessica Kerr talking productivity:
What makes a software engineer productive? You can list attributes like experience with the language, scientific mindset, intelligence, focus, a personally crafted IDE setup. Yet, in my experience, far and away the biggest factor is: familiarity with the codebase they’re changing.
This echoes some of our conversation with Jessica last year. She goes on to explain how the purple developer (pictured below) is 10x more productive than the others, not because they are inheritently better than them in some way, but because they are the ones who built the system in the first place.