3-4 years is very short as far as software lifespans go. Software libraries that are 10-15 years old are commonplace in both open source and at FAANGs, and some

3-4 years is very short as far as software lifespans go. Software libraries that are 10-15 years old are commonplace in both open source and at FAANGs, and some industries practice "extreme longevity": any domain where you wouldn't be surprised to run into a mainframe is probably also running code with a 30 year+ lineage.