Harness Engineering Solves Execution—Not Governance

The shift from prompt engineering to harness engineering represents a critical architectural advancement, enabling autonomous systems to handle real-world complexity like retries, multi-tool coordination, and cross-session continuity. However, harnesses solve execution efficiency, not architectural governance—agents can still bypass design decisions (ADRs), reintroduce forbidden dependencies, or violate layering rules because enforcement mechanisms are missing. As autonomous workflows scale into production systems, this governance gap becomes a critical vulnerability.