I've spent my career mostly at startups, and I see a pattern in which some critical piece of code is written by one person. Over time, or because the author doe

I've spent my career mostly at startups, and I see a pattern in which some critical piece of code is written by one person. Over time, or because the author doesn't value (or recognize) clean abstractions, the code becomes impenetrable, and only the author can maintain it. But I can see how a series of owners can produce the same situation.