Software archaeology and technical debt

In Vernor Vinge’s 1999 novel A Deepness in the Sky the protagonist learns what it means to become a programmer–archaeologist:

Programming went back to the beginning of time… Behind all the top-level interfaces was layer under layer of support. Some of that software had been designed for wildly different situations. Every so often, the inconsistencies caused fatal accidents. Despite the romance of spaceflight, the most common accidents were simply caused by ancient, misused programs finally getting their revenge.

“We should rewrite it all,” said Pham.

“It’s been tried. But even the top levels of fleet system code are enormous. You and a thousand of your friends would have to work for a century or so to reproduce it. And guess what—even if you did, by the time you finished, you’d have your own set of inconsistencies. And you still wouldn’t be consistent with all the applications that might be needed now and then. The word for all this is ‘mature programming environment’.”

( I often think of this passage when taking on a new project… )