Monorepo vs Polyrepo: Team Productivity Impact (Real Data)
Your 40-engineer team maintains 34 repositories. Sound reasonable? We see this shape often. A typical developer in that configuration triggers 11.4 context switches per day between repositories — almost all invisible to the EM, each costing roughly 23 minutes of refocus time, per UC Irvine's Gloria Mark (The Cost of Interrupted Work, 2008) and subsequent replications. The same team post-monorepo migration: 3.2 switches per day. The productivity math is obvious; the cost math is where it gets interesting.
Both architectures work. Google runs the largest known monorepo (2 billion+ lines of code, ~85,000 engineers). Netflix runs thousands of polyrepos. The question isn't which is better in the abstract — it's which fits your team size, your CI budget, and your tolerance for coordination overhead.