Q1 replatforming: run reviews and UGC in parallel for 30 days

• Freeze SKU and handle mapping before you touch the theme.
• Run old and new storefronts with matched JSON-LD for at least two weeks of real traffic.
• Import reviews early; reattach UGC by product ID, not Instagram permalink.
• Keep a rights log export that survives the cutover—compliance does not pause for migrations.
• Read headless UGC and public JSON if you are decoupling the front end.

Week 0 (before parallel run)

Day −7 to −1: Inventory every proof source. Review app, UGC gallery, Instagram feed app, loyalty-driven posts, Bazaarvoice if enterprise. Use the post-holiday stack audit as the worksheet.

Export checklist:

• Full review CSV from Judge.me, Loox or Okendo (October comparison).
• UGC metadata: creator, SKU, consent date, channels allowed.
• Redirect map: old /products/ URLs to new handles.

Day −1: Turn off auto-sync jobs that create duplicate product IDs on the staging store.

Week 1 — Staging truth

Days 1–3: Install review app on staging first. Import a pilot collection only. Validate stars on PDP match Google Merchant Center feed.

Days 4–5: Place UGC module on staging PDP. Run Shopify product page checklist checks 8–14 (social proof zone and speed).

Days 6–7: Schema validation. Compare rendered HTML, not just Rich Results test on a perfect URL. Agents read what shoppers get on mobile data.

Week 2 — Parallel traffic

Days 8–10: Soft launch new theme to 10% of traffic if your platform allows; otherwise use a password preview with QA crawlers.

Days 11–14: Monitor Search Console for structured data errors. Pair with multi-source reviews markup if you syndicate.

Parallel rule: If a SKU sells on both builds during testing, pick one source of truth for aggregateRating to avoid double-counting.

Week 3 — Cutover prep

Days 15–17: Full review import on production-new. Re-link UGC tiles. Run diff script: every active SKU should have ≥ the same proof count as old site.

Days 18–19: Email capture flows and Klaviyo blocks that embed UGC—swap domains and image hosts (Klaviyo vs Omnisend guide if you switch ESP at the same time).

Day 20: Rights log import into spreadsheet or Idukki—do not rely on “it is still on Instagram.”

Week 4 — Flip and watch

Days 21–22: DNS/theme flip in low-traffic window. Immediate 301 audit.

Days 23–25: PDP spot checks on top 20 revenue SKUs. Use fix one PDP element if proof slid below the fold in the new theme.

Days 26–28: AI referrer spot check—run three prompts in Perplexity for hero products; compare to pre-migration baseline (AI citation checklist).

Days 29–30: Retrospective doc for agency retainer (2027 UGC retainer scope).

Enterprise detour

If you leave Bazaarvoice mid-migration, follow the Bazaarvoice → Idukki 30-day plan instead of improvising SKU matching.

What not to do

• Do not launch a new theme the same week you change review apps unless you enjoy debugging two variables at once.
• Do not delete the old widget until redirects and imports validate—gallery URLs are bookmarked by email campaigns.
• Do not skip 2027 compliance re-attestation on imported reviews.

Roles during parallel run

Staging vs production pitfalls

Duplicate GTINs on staging pollute Merchant Center if feeds are connected—disconnect feeds until production is canonical. Review counts doubling when both themes expose widgets—use noindex or password on old theme except for QA IPs.

If you run headless, read headless UGC and public JSON before you assume the Shopify theme app embed still applies.

Data you must not lose

• Creator consent timestamps and channel list
• Whitelisting end dates for paid social
• Review syndication tokens and Google program enrollment
• Shoppable video attribution settings (12-question video test)

Post-cutover 48-hour war room

Hour 0–8: top 50 SKU PDP visual check + add-to-cart. Hour 8–24: structured data error report. Hour 24–48: email and SMS modules that embed UGC—swap CDN URLs if domain changed.

Document everything for the client’s 2027 retainer handoff.

Checklist export (printable)

• SKU/handle map signed by merchandising
• Review CSV from old store archived
• UGC rights export with consent dates
• Staging JSON-LD validated on pilot SKU
• 301 list deployed day of cutover
• AI referrer baseline captured pre-flip

Roles during parallel run

Staging vs production pitfalls

Duplicate GTINs on staging pollute Merchant Center if feeds are connected—disconnect feeds until production is canonical. Review counts doubling when both themes expose widgets—use noindex or password on old theme except for QA IPs.

If you run headless, read headless UGC and public JSON before you assume the Shopify theme app embed still applies.

Data you must not lose

• Creator consent timestamps and channel list
• Whitelisting end dates for paid social
• Review syndication tokens and Google program enrollment
• Shoppable video attribution settings (12-question video test)

Post-cutover 48-hour war room

Hour 0–8: top 50 SKU PDP visual check + add-to-cart. Hour 8–24: structured data error report. Hour 24–48: email and SMS modules that embed UGC—swap CDN URLs if domain changed.

Document everything for the client’s 2027 retainer handoff.

Parallel runs feel slow. They are faster than recovering organic citations and Merchant Center disapprovals in March.

Vendor escalation paths

If review import fails mid-cutover, open tickets with both review vendor and theme agency in one thread—prevents finger-pointing while PDPs show zero stars.

SEO and AI baseline

Capture weekly Search Console structured-data errors and three AI shopping prompts pre/post flip. Replatforming regressions show up in citations before they show up in revenue (agent teardowns).