// outline - full essay drafting; takeaways and bridge below
Many AI programs over-index on model choice and underinvest in the execution surface around the model.
This piece positions the harness as the strategic product: loop, tools, files, permissions, context, memory access, routing, sandboxes, stop rules, evidence, and workflow boundaries.
CTO: Build the execution wrapper you control, not workflows that belong to a vendor.
CIO: Vendor flexibility is an architecture outcome, not a procurement clause.
AI leader: Stop selling better prompts. Start designing the execution environment.
But the harness must not become the brain. The durable IP should live in skills.