The migration framework

A whole-home migration isn’t one big task — it’s a sequence designed to de-risk early and never break the house. This is the repeatable model the rest of the guide hangs on.

Start here:

• The 5-stage model — Discovery → prove the hard part → parallel operation → cutover → operate. The goal and the question for every stage, plus the exit criteria for the four that end.
• Principles — The cross-cutting rules that hold across every house: automate against reality, idempotency or bust, one source of truth, and the rest.

The stages, in depth:

• Stage 1 — Discovery & inventory
• Stage 2 — Prove the hard part first
• Stage 3 — Parallel operation
• Stage 4 — Cutover & decommission
• Stage 5 — Operate & harden

When something bites you mid-migration, the gotchas are the field dressing.