# AI RPG Migration Can Compile and Still Break Business Logic

DevFeed: [AI RPG Migration Can Compile and Still Break Business Logic](<https://devfeed.tech/articles/ai-rpg-migration-can-compile-and-still-break-business-logic-20744.md>)

Original publisher: [Read original article](<https://tomassetti.me/ai-rpg-migration-semantic-gap/>)

Author: Federico Tomassetti

Published: 2026-06-30T08:00:00Z

Content type: opinion

Language: en

Sources: [Federico Tomassetti](<https://devfeed.tech/sources/federico-tomassetti.md>)

Topics: [migration](<https://devfeed.tech/topics/migration.md>), [AI-assisted coding](<https://devfeed.tech/topics/ai-assisted-coding.md>), [Benchmark](<https://devfeed.tech/topics/benchmark.md>), [Code](<https://devfeed.tech/topics/code.md>)

Tags: [ai](<https://devfeed.tech/tags/ai.md>), [benchmarks](<https://devfeed.tech/tags/benchmarks.md>), [business-logic](<https://devfeed.tech/tags/business-logic.md>), [compilation](<https://devfeed.tech/tags/compilation.md>), [legacy-modernization](<https://devfeed.tech/tags/legacy-modernization.md>), [migration](<https://devfeed.tech/tags/migration.md>), [rpg](<https://devfeed.tech/tags/rpg.md>), [tests](<https://devfeed.tech/tags/tests.md>)

## AI overview

The article argues that AI-assisted RPG migration tools should be evaluated on behavioral equivalence, not only compilation and generated test-pass rates. It cites the AgentModernize study, where the best reported result reached 19.4% behavioral equivalence, and describes gaps between extracting business rules and implementing them faithfully.

## Source excerpt

AI-assisted RPG migration tools report high compilation success rates while silently failing on behavioral equivalence -- packed decimal truncation, activation group persistence, and cycle logic. The benchmarks show why, and what a real accuracy test looks like. The post AI RPG Migration Can Compile and Still Break Business Logic appeared first on Federico Tomassetti.