# Engineering notes

> Design notes about evidence, evaluation architecture and the boundaries behind Harbor Self-Evolving.

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LLMS index: [llms.txt](/harbor-self-evolving/llms.txt)

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Engineering notes explain why the product is designed this way. Formal shipped claims remain anchored to [Releases](https://istarwyh.github.io/harbor-self-evolving/releases/) and source evidence.

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Section pages:

- [Evidence before optimization](/harbor-self-evolving/blog/evidence-before-optimization/): Why an Agent needs validity, coverage and comparable identities before it needs another rewrite.
- [Host first, with honest boundaries](/harbor-self-evolving/blog/host-first-honest-boundaries/): Why 0.9.6 made Host execution the default without calling it a sandbox.