Every replatforming project teaches the same lessons, usually the hard way. Having run migrations across platforms and complexity levels, the patterns are consistent. Here are the ones worth learning before your project rather than during it.
The one-click import is a trap
Automated import tools are fine for the easy 80%: products, basic customers, recent orders. They quietly drop the 20% that carries the most risk, store credit, active subscriptions, affiliate history, complex product types, and you find out after launch when a customer complains. Treat each of those as its own workstream from the start.
SEO is a redirect project, not an afterthought
The biggest cause of post-launch traffic loss is not the new platform, it is URLs that changed without a 301. Build the redirect map from a crawl, the platform's URL data and Search Console, verify the top pages individually, and avoid chains. This is the single highest-leverage thing you can get right, and it is covered in SEO preservation.
Data is dirtier than you think
Every store underestimates how messy its data is: duplicate customers, malformed records, products with missing attributes, abandoned SKUs. Migrating without cleaning first means importing years of mess into a fresh store. Audit and clean before import, not after, as described in data audits and cleanup.
Integrations fail on ownership, not connectivity
When ERP, accounting and fulfillment reconnect, the failures come from two systems disagreeing on who owns a field, so they overwrite each other. Decide the source of truth for every field before building, and make syncs idempotent so a retry never double-posts.
Cutover is the moment of truth
Improvised cutovers cause the war stories. Freeze data at a known point, run a final delta, verify redirects and integrations on staging, switch on a runbook, and keep a rollback path. Then watch closely for 48 hours. A rehearsed cutover is calm; an unrehearsed one is a scramble.
Scope by complexity, not record count
Timelines are driven by subscriptions, B2B pricing, integrations and redirect volume, not by how many products you have. A 500-SKU store with subscriptions and wholesale is harder than a 50,000-SKU catalog with none. Be honest about complexity when you plan.
The full method is on the Shopify migration hub, with a program view in launch and replatform. The projects that go smoothly are the ones that respected these lessons up front.