I mean, i spent 20 months working on a project for a bank recently. I had a lot of salient code at the beginning, fun little algorithms and cool regex.
The last iteration of the code i committed, the salient part was basically a lisp interpreter (if lisp was formatted like json), but everything else was plain and boring. The last issue i had is that the ES version was upgraded and the python library i used to connect to ES was version locked, and did not work.
I think that for the next 4 years, this will be the only type of modifications my SRE ex-collegue who now own the code will make. Still, it can take days.
Nothing really had any outsized impact in the last 12 months of the project imho. Once the minimum viable product was done, every bit of improvement i did was either simplifying, performance-related or adding more configurability (and test, and documentation).
I did a piece of code that adapted to the ES request that i really like and could be showed off, but it took me three weeks, but 90% of what i parametrized could be hardcoded and it would have changed nothing in the long run.
10 lines of salient code could be the entry point into some subsystem you wrote, or where you integrate with another system. It wouldn’t look fancy but it’s salient.