Evidence changes the unit of delivery

For years, modernization programs were judged by whether the target application looked equivalent at the surface. That standard is no longer enough. When AI participates in the rewrite, every generated line needs a reason that can be inspected, challenged, and reproduced.

Holonic starts by decomposing the existing system into source-derived intent. The intent model becomes a queryable contract: what behavior exists, where it came from, which assumptions support it, and which outputs must preserve it.

Review should be line-by-line

A useful evidence package does not ask reviewers to trust an opaque transformation. It gives them a structured path from modern code back to legacy source, intent assertions, transformation rationale, and acceptance checks. The result is not just modern code in weeks. It is modern code with proof.