Or it's well architected. Most of the time, developers are ideally working on new value additions rather than pure maintenance. The problem happens when someth

Or it's well architected. Most of the time, developers are ideally working on new value additions rather than pure maintenance. The problem happens when something breaks - let's say your database changes the execution plan and it crawls to a halt. I've seen this happen out of the blue and it was a few hours of work to figure out a solution. If you don't have a developer who understands the code, you might be sunk.