Uber infamously runs thousands of microservices because hundreds of engineers wanted independent deployment. Previously, small teams of 5-10 people generating 50 commits/20 pushes/10 PRs daily didn't need this modularity.
Today, a small team running 20-100 agents might generate 500 commits/200 pushes/100 PRs. Uber's approach may become the new normal. The more modular your code, the more agents you can run in parallel. Monoliths cause merge conflicts; microservices enable "embarrassingly parallel" work.
100+ agents must work independently or productivity turns net-negative. Splitting services used to be expensive—boilerplate, plumbing, CI config. Agents write all that now. Agents are also context-limited; modules fitting in the context window dramatically improve performance.
Your codebase's modularity determines how many coding agents you can run effectively, so it's worth designing for it from the beginning.
Source: Hacker News · Summarized by HeadlinesBriefing