Migrate tech stacks with AI by preserving observable behavior while replacing one bounded layer at a time. Begin with an inventory of entry points, dependencies, data formats, integrations, build steps, and unsupported assumptions. Ask the agent to produce a migration plan before generating replacement code.
Define compatibility contracts for APIs, events, database records, configuration, and user-visible behavior. Add characterization tests around the current system, including error cases. Choose a first slice that is valuable but reversible, then keep old and new paths comparable through fixtures, contract tests, or shadow traffic where appropriate. Separate mechanical conversion from design changes and dependency upgrades. Require the agent to record mappings between old and new components, commands run, failed checks, and unresolved behavior. For data migrations, rehearse backup, forward migration, verification, and rollback on production-like data.
Track migrated behavior, not converted files. Useful measures include contract coverage, unresolved differences, rollback time, defects, review effort, and the amount of old code safely removed. A broad rewrite can look fast until integration begins.
Use AI to accelerate inventory, translation, tests, and discrepancy analysis, while humans approve architecture and release gates. Finish each slice with evidence that both behavior and recovery work. That creates a migration you can pause, inspect, and resume instead of a single irreversible leap.
