A Java engineer verifies an agent’s migration with visual evidence

Java practitioner Patrick Baumgartner describes migrating roughly 900 teaching slides from Reveal.js to Marp with Copilot, using screenshots, visual comparisons, side-by-side animation checks and generated PDFs to verify the result. He reports eight to ten hours of work. The useful pattern is defining what must survive the migration and asking for evidence at each gate; this interview does not establish a general productivity multiplier.

GitHub · Oct 20, 2026

Why it matters

An agent’s completion message is weaker evidence than checks tailored to the behavior the user needs to preserve.

More context

This card covers Baumgartner’s migration and verification sections of GitHub’s three-person interview. His broader workflow pairs model output with deterministic checks such as Checkstyle, PMD and architecture tests, while retaining hands-on application review.

Keep in mind

The timing is a practitioner’s account in a vendor-published interview, not a controlled comparison. Visual diffs alone cannot verify interactive behavior or unchanged meaning.

Original read