This pillar maps the categories and points to the live shortlists. Each category has a small set of legitimate tools, and most of the decision-making is about engagement model and fit, not feature comparison.
The most common operator mistake at this stage is over-evaluating the tools and under-evaluating the partners. The tooling decisions are largely solved problems within each category; the partner decision is where outcomes are determined.
Automated migration apps
Three vendors dominate the automated migration category: Cart2Cart, LitExtension, and Next-Cart. Functional parity is the working assumption. The differentiator is engagement model — Cart2Cart leans self-service, LitExtension offers a managed-service tier, Next-Cart is comparable to both. Output quality is comparable across all three.
The right pick is rarely about which wizard has more features. It is about which vendor has the live operator the brand can reach during cutover weekend, which agency network the brand is plugged into, and which vendor has recent references at the brand size. Get three quotes, check references, decide on that basis.
Above the simplest catalogs, the automated tools are not the whole answer. They handle the seed load; Matrixify handles the reconciliation; an iPaaS handles dual-write if the cutover is not single-weekend. The toolchain is layered, not single-vendor.
iPaaS for ongoing data flows
iPaaS becomes the right answer when the cutover is not a single event but a sustained dual-write where two stores need to stay in sync for weeks. Three vendors cover most of the market at this brand size: Celigo (mid-market), Boomi (enterprise), and MuleSoft (enterprise, Salesforce-platform context).
The expense is meaningful — five-figure annual commitment for Celigo, more for Boomi or MuleSoft. The decision criteria are existing iPaaS footprint, whether the brand wants to extend or replace it, and what the post-migration architecture looks like. Brands picking iPaaS solely for the migration almost always under-leverage it.
For single-weekend cutovers, iPaaS is unnecessary and skipping it saves real money. For multi-week dual-write engagements, iPaaS is essential and skipping it almost guarantees data drift during the overlap period.
Replatforming partners and agencies
Above $10M brand size, replatforming is almost always partner-led. The Shopify Plus partner ecosystem has consolidated around a handful of agencies for the mid-market and a smaller set for enterprise. Source-platform specialists (Magento, WooCommerce) overlap with general Plus partners but are not interchangeable for complex source-platform engagements.
The partner-selection criteria that matter: brand-size fit (a $50M agency running a $5M engagement carries overhead the brand pays for), engagement model (full-service versus split), geography and timezone overlap with cutover weekend, and the depth of source-platform experience on the proposed engagement team specifically.
Reference checks at the brand's revenue size are the only signal that consistently works. Capability decks and Plus partner badges filter the candidate set; references determine the pick. Ask for both a smooth migration and a difficult one at your size, and talk to both — the patterns the agency names tell you more than any deck.
Adjacent tools that earn shortlist slots
A few tools that are not migration-specific earn shortlist slots because they are part of the migration toolchain in practice: Rewind for backups during cutover weeks, Easy Redirects for post-cutover redirect operations, and Matrixify for bulk operations across the engagement. None of these are strictly "migration tools" — they are operational tools that get installed during migration and stay in the post-launch stack.
Theme migration is its own narrow category. Most brands rebuild the storefront from a Shopify theme template rather than attempt to migrate the source-platform theme. Theme migration tools exist but are rarely the right call at $5M+ — the rebuild is faster and produces a cleaner result than trying to translate a Magento or WooCommerce theme to Shopify.