Shopify Migration Timeline for Established DTC Brands

If your store is already doing serious revenue on Magento, BigCommerce, WooCommerce, or a custom stack, "just migrating to Shopify" is not a weekend project. The platform switch is the easy part. Protecting your traffic, your subscriptions, your ERP integrations, and your team's sanity is the work.

Here is the timeline we use with established brands replatforming onto Shopify and Shopify Plus, anchored in real engagements like Petwell (large pet-vertical catalog) and Llantas Cavazos (industrial tire retailer in Mexico with payment-gateway and inventory complexity).

Phase 1 — Discovery & data audit (weeks 1–2)

• Inventory every integration: ERP, 3PL, ESP, reviews, subscriptions, loyalty, CDP.
• Export and clean catalog data: products, variants, metafields, redirects, customer accounts. For Petwell, this phase took longer than initially scoped because the legacy catalog had thousands of SKUs with inconsistent variant naming — a pattern we now plan for whenever a brand has more than a few thousand active SKUs.
• Map every URL on the current site. This becomes your redirect plan. See Shopify's URL redirect documentation for the import format.
• Decide: Shopify or Shopify Plus? Plus is required for B2B, custom checkout, multi-store, and >$1M GMV with tax/wholesale complexity.

Phase 2 — Theme & checkout build (weeks 3–6)

• Build on a modern Online Store 2.0 theme or headless if your team can support it. Shopify's theme architecture docs are the canonical reference.
• Rebuild PDP, PLP, cart, and account flows. Do not lift-and-shift the old design — most of the conversion lift comes here.
• Configure checkout extensibility (Plus) for any custom logic that used to live in checkout.liquid.

Phase 3 — Integrations & data import (weeks 4–7, parallel)

• Wire ERP/3PL through Shopify Flow, native connectors, or middleware. For Llantas Cavazos, the hard part was not Shopify itself — it was reconciling a Mexico-based payment gateway (Mercado Pago + bank installments) with the existing inventory system, which required a custom middleware layer that ran in parallel for two weeks before cutover.
• Import historical orders for customer continuity using Shopify's migration guide and tools like Matrixify for large catalogs.
• Migrate subscriptions cleanly — Recharge, Skio, or Shopify Subscriptions, with a tested customer-comm plan.

Phase 4 — QA, redirects, soft launch (week 8)

• 301 every old URL. This is where most brands lose 20–40% of organic traffic if rushed. Petwell preserved organic by mapping every legacy collection URL one-to-one before DNS swap; the brands that skip this step routinely take a quarter to recover.
• Run a staging cutover with a real subset of traffic.
• Pixel parity: GA4, Meta CAPI, TikTok, Klaviyo events all firing identically.

Phase 5 — Cutover & stabilization (week 9 + 30 days)

• DNS swap during your lowest-traffic window.
• Monitor Search Console, conversion rate, and AOV for 30 days. Expect a 1–2 week dip; full recovery in 4–6 weeks if redirects and schema were done right.

What goes wrong

• Redirects done as an afterthought. Plan them in Phase 1, not Phase 4.
• Subscription migration without customer comms. Churn spikes if customers don't know.
• Forgetting metafields. They drive your PDP. Map them before you import.
• Underestimating large catalogs. Anything over a few thousand active SKUs needs its own sub-timeline for data normalization, taxonomy mapping, and image migration.
• Payment gateway assumptions in non-US markets. What works in the US (Shop Pay, Stripe) often doesn't map cleanly to local rails in Mexico, Brazil, or Southeast Asia.

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If you're scoping a Shopify or Shopify Plus migration, get a quote and we'll build the timeline against your actual stack.

As of early 2026, Shopify migrations have transitioned from simple data transfers to deep infrastructure overhauls. The technical landscape is defined by the absolute deprecation of Shopify Scripts (sunset for new installs August 28, 2025; full end-of-life June 30, 2026), requiring all migrating Plus brands to shift logic into Shopify Functions. Custom discount or shipping rules that lived in Ruby scripts on legacy platforms must now be rebuilt as WebAssembly Functions before cutover.

Economic milestones in Q1 2026 show Shopify's ecosystem capturing a larger share of enterprise GMV, driven largely by Checkout Extensibility. Modern migrations now prioritize UI extensions and the Model Context Protocol (MCP) for agentic commerce, allowing AI-driven shopping assistants to interact directly with the storefront's product discovery layer from day one of cutover.

Frequently asked questions

How is product data mapping handled for large catalogs?

While Shopify provides native CSV import tools, established brands typically use Transporter (for Plus) or third-party middleware like Matrixify. The complexity lies in mapping metafields — custom data fields for specifications or internal ERP IDs. In 2026, it is critical to ensure your product data matches the new Shopify Taxonomy to leverage automated collection filtering and improved SEO signals immediately upon launch.

What happened to custom checkout scripts in 2026?

For brands on Shopify Plus, custom checkout logic such as "Buy X, Get Y" or complex shipping bundles is now handled via Shopify Functions. Shopify Scripts (Ruby-based) sunset for new installs in August 2025 and reach full end-of-life June 30, 2026. Migrating brands must ensure their legacy business logic is rewritten into Functions using Rust or JavaScript before the DNS cutover to avoid breaking the customer experience.

How do we prevent organic traffic loss during the migration?

Prioritize 301 redirects and Schema.org markup. A common failure point is the collection URL structure difference between Shopify and platforms like Magento. Use a mapping tool to ensure every legacy URL points to its nearest Shopify equivalent, and monitor Google Search Console for 404 errors during the first 14 days post-launch.

Should we migrate to a standard theme or a headless (Hydrogen) build?

High-volume brands often choose Hydrogen (Shopify's Remix-based framework) for a headless architecture. This allows for superior performance and creative freedom but adds significant development time. If sub-second page loads and a unique frontend are the priority, Hydrogen on Oxygen is the standard; otherwise, a Liquid-based Online Store 2.0 theme is faster to deploy.

Further reading

• Shopify Help Center: Migrating to Shopify
• Shopify themes documentation
• URL redirects in Shopify