In a series of books by David Brin [0] there is a galaxy-wide institution known as the library, and civilizations regularly mine its millions of years of data for suddenly-relevant-again techniques and technologies.
I remember one bit where a species had launched some tricky fleet-destroying weapon to surprise their enemies with esoteric physics, only to have it reversed against them, possibly because the Librarian that once helped their research-agent wasn't entirely unbiased.
Also in Vinge's Deepness in the Sky, there aren't really "programmers" as we know them anymore, but "programmer-archeologists" that just search the archives for code components to reuse.
I think that's unfair to the programmer-archaeologists: young Pham wanted to write things from scratch (and took advantage when he got a chance to), and other characters said he was a talented hacker, but as they also said, it was just way more productive most of the time to cobble together ancient code.
That's pretty much what any (decent) programmer does today as well. You first search your code base to see if the application already does something like it, if not, whether there is a published library. Where this starts to fail is the idea that connecting those already written peaces together is easy.
Also: In the Destiny mythic sci-fi franchise, the human golden age ended with a mysterious apocalypse, leaving "cryptarchs" (crypto-archeologists) to try to rebuild from arcane fragments of encrypted data or unknown formats.
Don't worry, it's nowhere near the main plot or characters, just a small "meanwhile, elsewhere" vignette. Basically emphasizing the "why bother everything's already invented" mentality of most client-races, and how deep access and query-secrecy have big impacts.
I remember one bit where a species had launched some tricky fleet-destroying weapon to surprise their enemies with esoteric physics, only to have it reversed against them, possibly because the Librarian that once helped their research-agent wasn't entirely unbiased.
[0] https://en.m.wikipedia.org/wiki/Uplift_Universe