Migration checklist

The whole switch, in order, with the rollback point marked at every step.

Before you start#

• [ ] Duplicate your published theme. All widget work happens on the copy.
• [ ] Note your five most-searched vehicles and ten best-selling SKUs — this is your test set.
• [ ] Export your current app's analytics if you want to keep the history.
• [ ] Confirm who can edit the theme and who can install apps.

Week one — run in parallel#

• [ ] Install WySync. Confirm the first index finished and the count matches Shopify.
• [ ] Turn on the migration switcher.
• [ ] Connect any sources you already own — tags, a supplier CSV, a sheet.
• [ ] Map your metafields for filters.
• [ ] Check fitment coverage on the dashboard. Under 60% means keep going.

Rollback: uninstall WySync. Nothing on your storefront has changed.

Week two — build the storefront on the duplicate theme#

• [ ] Enable the WySync app bootstrap embed.
• [ ] Add the YMMS hero to the homepage.
• [ ] Add the collection list block to /collections, and map your collections.
• [ ] Replace the product grid with the WySync collection block.
• [ ] Add the product fits check and fitment table.
• [ ] Add cart re-verification and decide on the checkout gate.
• [ ] Style everything to match the theme.

Rollback: the duplicate is never published. Your live store is untouched.

Week two — verify#

• [ ] For each of your five test vehicles: hero → collection list → grid → product → cart.
• [ ] For each of your ten test SKUs: does the verdict match what you know to be true?
• [ ] Compare a filtered collection count against the incumbent's for the same vehicle. Large gaps are worth understanding before you publish.
• [ ] Check the fitment table on a wide-fitment SKU and a narrow one.
• [ ] Test on a real phone, not a resized desktop window.

Cutover day#

• [ ] Publish the duplicate theme.
• [ ] Re-run the five-vehicle walkthrough on the live store.
• [ ] Watch the dashboard for an hour: searches and vehicle selections should start immediately.
• [ ] Leave the old app installed but with its blocks removed.

Rollback: republish the previous theme. Two clicks, immediate.

One week later#

• [ ] Review zero-result queries and add synonyms.
• [ ] Review the editor's no-fitment list, sorted by revenue.
• [ ] Then, and only then, cancel the old subscription.