How Team Size Affects Productivity: Brooks's Law in Real Data

"Adding manpower to a late software project makes it later." Fred Brooks wrote that in 1975. Fifty years later, engineering leaders still debate whether it's true. We looked at real coding data from 100+ B2B companies on PanDev Metrics to understand how team size relates to individual developer productivity. The answer is more nuanced than Brooks suggested — but his core insight still holds. The Original Argument Brooks's Law, from The Mythical Man-Month (1975), rests on two observations: Commun