Cutover Diary: The Leftovers When You Move an AI Workflow to Free Infrastructure

Description and use

Migrating an AI bot to free infrastructure required careful planning: freezing the old config, shadow testing, and incremental traffic shift. After fixing leftover retry logic, prompt template, and scheduling, the migration succeeded.

Problem

Migrating an AI review bot from a paid endpoint and VPS to free infrastructure introduced hidden issues such as leftover retry logic, prompt formatting, and scheduling mismatches.

Outcome

The migration succeeded after addressing three key leftovers: reworked retry logic, prompt template, and cron schedule. Shadow mode revealed prompt formatting differences, and a week of overlap ensured stability before decommissioning the paid endpoint.

Workflow

• Freeze old configuration and snapshot prompt, retry policy, and server setup
• Run shadow mode to compare outputs of old and new pipelines
• Flip traffic for a single repository to test live performance
• Keep old server alive for seven days as rollback target
• Delete old endpoint after a full week of successful reviews

Evidence

The plan had five steps, and the order matters because each one gives you a way back

Source

Three things did not migrate cleanly, and each one is a lesson about free infrastructure

Source