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AI code migrations, because it shouldn't have to be so much work. https://tern.sh
Writing code is easier than editing code, for humans and for AI.

The leverage isn't in the generated code. It's in encoding your expertise into a system you can run at scale.

Full write-up: tern.sh/blog/ai-code...
A Workflow for Trusting AI Code at Scale | Tern Blog
When a teammate opens a PR, the work is 90% done. When an AI opens a PR, that's not true. The work is maybe 10% done. <br /><br />This is the central problem of AI code migrations: a bot can change…
tern.sh
December 16, 2025 at 10:03 PM
The loop: run a batch → find the pattern in failures → fix the prompt → re-run and measure → repeat.

It feels like programming because it is. You're tightening a spec until the output is indistinguishable from code your team would write.
December 16, 2025 at 10:03 PM
The counterintuitive part: you don't build trust by reviewing every file. You build it by finding your workflow's failure modes.

If step 2 fails on async tests, that's one bug in your instructions. Fix it, regenerate everything.
December 16, 2025 at 10:03 PM
Step two: treat your prompt like a program, not a wish.

Migrations need stages: gather context, transform, validate, fix errors. One mega-prompt overloads the AI and makes failures impossible to debug.
December 16, 2025 at 10:03 PM
Step one: turn the overwhelming problem into a spreadsheet. Find the call sites, tag complexity, note which files don't actually need changes.

You haven't started the migration. You've just gotten smarter about the problem.
December 16, 2025 at 10:03 PM
This is the central problem of AI migrations: a bot can change 500 files overnight, but you're left with 50,000 lines of potential garbage to review.

Better models don't fix this. The fix is a workflow.
December 16, 2025 at 10:03 PM