Measuring programmer productivity, as in long-term impact, is much harder than measuring how many hours Programmer X sits at their desk or how many lines of cod

Measuring programmer productivity, as in long-term impact, is much harder than measuring how many hours Programmer X sits at their desk or how many lines of code they can spit out in a day. Those are metrics that other programmers notice after maintaining code that previous programmers leave behind. It's always going to be a delayed reaction.