Measures of developer productivity

The most used metrics are

1. lines of code (LOC) per unit time (Delorey, Knutson, & Chun, 2007; Maxwell, Van Wassenhove, & Dutta, Oct 1996) 
2. Function points per unit time (Delorey et al., 2007; Maxwell & Forselius, 2000).
3. Number of diffs landed per unit time (Facebook, Uber)