The Shopify Plus Migration Playbook: Zero Downtime, Zero Data Loss

Platform migrations have a well-deserved reputation for going wrong. They take longer than planned, lose data in transit, tank search rankings, and occasionally bring down a brand's revenue for days. Migrations from Magento 1, Magento 2, BigCommerce, WooCommerce, SFCC, and custom platforms all follow predictable failure patterns — and equally predictable ways to prevent them.

This is the playbook.

The Foundation: Treat Every Migration Like Surgery

The mindset that prevents migration disasters: treat the production store as a patient on an operating table. The goal is to complete the procedure without unexpected complications, and to have the patient fully recovered by the time they leave. Every step is deliberate, every action is logged, and the surgical team is aligned before the first incision.

That means:

• No improvisation on migration day
• Every step executed by two people (one acting, one verifying)
• Rollback plan ready and tested before cutover
• Operations team briefed and on standby

Phase 1: Discovery (Weeks 1-2)

Before moving anything, build a complete inventory.

Data Inventory

Document every object type that needs to migrate:

• Products: Variant count, metafields, custom attributes, image/video assets
• Customers: Account types, address count, loyalty points (if applicable)
• Orders: Historical order count, period coverage, fulfillment statuses
• Content: Pages, blog posts, navigation menus, redirects
• Discount codes: Types, usage limits, expiration dates, usage counts
• Gift cards: Remaining balances

For each object type, document the source schema and map it to the Shopify schema. Identify fields with no direct mapping (these are your migration complexity hotspots).

SEO Asset Inventory

Run a full crawl of the source site with Screaming Frog:

• Every indexed URL with its current title, meta description, and canonical
• Internal link count (identifies high-authority pages)
• Structured data markup in place
• Core Web Vitals baseline (Google PageSpeed)

Pull Google Search Console data:

• Top 100 pages by organic traffic
• Search queries and current positions
• Current impressions and clicks baseline

This SEO snapshot is your before state. You'll compare it against the post-migration state to catch any issues before they compound.

Integration Inventory

List every system connected to the current platform:

• ERPs and inventory management systems
• Email marketing (Klaviyo, Mailchimp)
• Customer service platforms (Gorgias, Zendesk)
• Analytics (GA4, Segment)
• Reviews (Yotpo, Okendo)
• Loyalty (LoyaltyLion, Smile)
• Payment gateways
• Tax compliance (Avalara, TaxJar)

For each integration, identify the migration work required: reconfiguration, new app installation, or custom API reconnection.

Phase 2: Destination Build (Weeks 3-8)

Build the Shopify Plus store in parallel. The source store continues operating normally throughout.

Theme Development

The theme is built against your complete product catalog and tested with real data. Specific areas to test:

• Product page rendering for edge cases (products with 200+ variants, products with no images, products with custom metafield data)
• Collection page performance with large catalogs
• Search functionality and filters
• Mobile experience across iOS and Android

Data Migration Pipeline

Build and test the migration scripts against a staging environment:

1. Export all product data from source platform via API or database export
2. Transform data to Shopify's schema using custom scripts
3. Import to Shopify via the Admin API (using bulk operations for large catalogs)
4. Validate: compare record counts and spot-check individual records for accuracy

Run this pipeline repeatedly. By migration day, you should have run it 5+ times and refined any edge cases.

301 Redirect Map

Build a complete redirect map: every source URL → corresponding Shopify URL. For large sites, this is automated: extract all source URLs, map to Shopify URL patterns (product handle, collection handle, page handle), validate that the destination URLs exist.

Test the redirect map before cutover by running the full source URL list against the staging environment.

Phase 3: Parallel Testing (Weeks 9-10)

Run the destination store in shadow mode: real data, no customer traffic.

Functional Testing Matrix

Test everything:

• All payment methods (credit card, Shop Pay, Afterpay, PayPal)
• All discount types and code formats
• Gift card redemption
• Customer account login, registration, order history
• Checkout with every combination of shipping options
• All third-party app integrations

Sign off on each item. Nothing goes live with open issues.

Performance Testing

Run Lighthouse and PageSpeed against the destination store and compare to the source baseline. If performance regresses significantly on key pages, investigate before cutover.

Phase 4: Cutover

Plan for a 2-4 hour maintenance window during your lowest-traffic period (typically 2-5am in your primary market).

Cutover Checklist

1. Final data sync: Export all records created since last migration run, import to Shopify
2. Enable maintenance mode on source store
3. Final validation: Verify record counts match
4. DNS cutover: Update A/CNAME records with short TTL (300 seconds)
5. SSL verification: Confirm Shopify SSL certificate is active for your domain
6. Smoke test: Add to cart, checkout, verify payment on the live store
7. Monitor: Watch error rates, order volume, and checkout conversion for 30 minutes
8. All clear: Brief operations team that migration is complete

If any critical issue is found during the maintenance window, DNS rollback is possible within 5 minutes.

Phase 5: Post-Migration (Days 1-30)

First 48 Hours

• Watch Google Search Console for crawl errors (check hourly)
• Monitor Shopify's order flow and checkout conversion vs. baseline
• Review customer service inbox for migration-related issues

Weeks 1-4

• Check GSC weekly for ranking changes on top 100 organic pages
• Monitor site speed (PageSpeed Insights) for any regression
• Run a fresh crawl and compare to pre-migration crawl for redirect compliance

Most SEO impact from well-executed migrations is temporary. With proper redirects and continued optimization, rankings typically recover within 4-8 weeks.