Lawrence Kesteltoot on Norris Numbers:
My friend Clift Norris has identified a fundamental constant that I call Norris’ number, the average amount of code an untrained programmer can write before he or she hits a wall. Clift estimates this as 1,500 lines. Beyond that the code becomes so tangled that the author cannot debug or modify it without herculean effort.
The idea is the programming skills needed to write and maintain a 20,000-line codebase are very different from those needed for a 2,000-line codebase. Each time the size of your codebase goes up by an order of magnitude you need a new set of skills to be able to be successful in it.
Reminds of the rule of 3 and 10 for company size.