Same feature, same verification, two architectures. What three coding-agent codebases converge on, and why Clean Architecture isn’t wrong, just answering the old question.” series: Grounded Code First of five articles in the **Grounded Code * series. Architecture principles for codebases primarily extended by agents.* I. The number nobody was measuring Same task. Same agent (Claude). Same final output, with Verification: ✅ on both runs. The difference is in the middle column. Metric agent-opt clean-ddd ratio Wall clock 73s 329s 4.5x Turns 17 52 3.1x Total tokens 230,858 1,722,500 7.5x Cache reads 195,489 1,652,055 8.5x Output tokens 3,882 16,941 4.4x Verification ✅ ✅ — The first column is a codebase organized around conventions tuned for the agent that’s going to extend the code. The second is the same feature, same stack, organized with Clean Architecture and Domain-Driven Design: layers, ports and adapters, separation by responsibility, ubiquitous language.…