CONCEPT
Brooks's Law
Adding manpower to a late software project makes it later. The 1975 observation whose communication-overhead mathematics predicted both the failure of team-based scaling and the theoretical superiority of the solo builder.
Brooks's Law emerged from the painful lessons of OS/360, the System/360 operating system project Brooks managed at IBM in the 1960s. Its arithmetic is unforgiving: a team of n people requires n(n−1)/2 communication channels. Four people need six channels. Fifty need 1,225. The additional capacity each new person brings is consumed — and more than consumed — by the overhead of coordinating her work with everyone else's. Beyond a threshold, the net contribution of each new person is negative. The law held through every subsequent transition because communication overhead is not a property of the tools. It is a property of the people. Its most radical implication was always that the theoretically optimal team is one — because the communication overhead drops to zero. This implication was theoretical in 1975. In 2026, it is operational.
In The You On AI Field Guide
The law's confirmation by the AI transition is stronger than its celebrators typically recognize. Brooks's Law was never refuted by the solo