Series

Harness Engineering: The Compounding Stack

The model is the CPU. The context is the RAM. The harness is the OS. When models commoditize, the harness becomes the moat. A 13-part series — this hub plus 12 chapters — mapping what to build, in what order, and why your competitor cannot copy it.

harness-engineering

Read this series in order.

Each part builds on the one before it. Reading time, level, and the concepts covered are shown for every part below.

SeniorAdvanced
13 articles
296 minutes
32 concepts

Parts

Articles in this series

13 parts
  1. Harness Engineering — What This Series Is, and Why You Should Read It in Order The harness is the OS layer models cannot give you. 12 minutes Senior start here
  2. What a Harness Actually Is (and What It Is Not) Separate the model CPU from the operating layer. 20 minutes Senior
  3. The Four Primitives Every Working Agent System Has Five systems converged on the same four primitives. 28 minutes Senior
  4. The Reasoning Sandwich: Why More Thinking Made My Agent Worse More reasoning in the wrong place made the agent worse. 18 minutes Senior
  5. Coordinator Mode: A Working Multi-Agent System, From the Source Claude Code's coordinator is a real multi-agent blueprint. 32 minutes Advanced start here
  6. Replay Safety: The Bug That Breaks Every HITL Workflow Replay turns approval workflows into duplicate side effects. 26 minutes Senior
  7. Skills as Information Architecture, Not Features The right markdown at the right time changed the pass rate. 22 minutes Senior
  8. Prompt Cache Is Architecture: Designing Around the 50K-Token Mistake Cache stability is a systems boundary, not an optimization. 22 minutes Senior
  9. The Session-Memory Feedback Loop (ACE + Codified Context) Sessions need a memory loop, not a longer prompt. 26 minutes Advanced
  10. The Org-Harness Thesis: Why Context Does Not Transfer The durable moat is workflow context competitors cannot copy. 26 minutes Advanced
  11. The Numbers That Killed the 'Wait for Better Models' Excuse The receipts say the harness moved the score, not the model. 14 minutes Senior
  12. Build Your Own Harness: A 6-Week Plan for a 3-Person Team A six-week plan for shipping the harness without boiling the platform. 30 minutes Advanced
  13. The Ten Pitfalls (and How to See Them Coming) Every pitfall has a symptom before it has a postmortem. 20 minutes Senior