Migration OS → AC — how complex, how much?

Less complex than a re-platform, more involved than a routine upgrade. Same database schema, vast majority of code carries over unchanged. What actually happens:

• License + Cloud activation — week 1.
• Extension audit: identify which OS-only extensions duplicate AC native modules (often 4–8 of them). Plan to remove or replace — 1–2 weeks.
• Schema reconcile: AC ships extra DB tables for staging / GiftCard / Rma / CustomerSegment. Setup:upgrade handles most; expect 1–2 days of edge cases.
• B2B re-platform: if you had OS B2B extensions, migrate data into Magento_Company tables — 1–3 weeks depending on volume.
• Page Builder content: existing CMS content stays as legacy WYSIWYG; new content uses Page Builder. No mass migration needed.
• Regression QA + cutover — 2 weeks.

Total: $30–100k all-in depending on customisation depth and extension count. 6–10 week project for a typical $10–30M store.