How to Assess a Shopify Merchant Before a Migration

Summary

Shopify migrations look straightforward until they aren't. A proper assessment uncovers the app dependencies, checkout customizations, and integration patterns that determine whether a migration is a two-month project or a six-month rebuild.

The Ecosystem Creates the Complexity

Shopify's strength is its ecosystem. Merchants extend functionality through apps, customize checkout through Shopify Functions and Checkout UI Extensions, and connect to external systems through a mix of native integrations and custom middleware.

A store that looks simple on the surface may have 40 apps, custom metafield structures powering the theme, and a checkout flow that depends on deprecated Script Editor scripts.

The assessment isn't about what the store does today. It's about understanding how it does it, and what breaks when you move to a new theme, upgrade to Checkout Extensibility, or migrate to a headless architecture.

App Inventory Reveals Load-Bearing Dependencies

Start with the full app list, but don't stop there. You need to understand:

Core vs. nice-to-have apps. Which apps are load-bearing? A loyalty program deeply integrated with checkout and email is different from a wishlist app with 12 users.
App data ownership. Where does the data live? Apps that store critical data outside Shopify (subscription platforms, reviews, customer data) create migration dependencies.
Deprecated or unsupported apps. Apps built on legacy APIs or Script Editor are ticking clocks. If the merchant is on Checkout.liquid, that's a migration within a migration.
App overlap and conflicts. Multiple apps doing similar things often indicate organic growth without governance, and hidden technical debt.

Export the app list programmatically. Cross-reference with Shopify's app documentation to flag anything built on deprecated technology.

Theme Architecture Shows Customization Debt

Themes tell you how customizable the storefront is and how much technical debt exists:

Theme version and framework. Is it a 2.0 theme with JSON templates and sections everywhere? Or an older theme with rigid Liquid templates?
Custom sections and blocks. Heavy customization in theme code means migration cost. Document what's custom vs. what came with the theme.
Metafield usage. Modern Shopify stores often use metafields to power dynamic content. Map metafield definitions, namespaces, and where they're referenced in the theme.
Third-party theme or custom build. Third-party themes from the Theme Store have predictable structures. Fully custom themes require deeper code review.

Look at the theme's config/settings_schema.json and section files to understand the customization surface area.

Checkout Customization Is Where Migrations Break

Shopify has moved through multiple checkout extensibility models, and merchants are often stuck on older approaches:

Script Editor usage. Discounts, shipping logic, payment customization, if it's in Script Editor, it needs to be rebuilt using Shopify Functions.
Checkout.liquid customization. If the merchant has a Plus store with checkout.liquid modifications, those won't survive a move to Checkout Extensibility. Document every modification.
Checkout UI Extensions. If they're already on Checkout Extensibility, understand what extensions are installed and what they do.
Post-purchase and thank you page customization. Often overlooked, but these pages may have tracking, upsells, or custom content that needs migration.

Get explicit about what checkout does today. Every conditional discount, every payment method restriction, every custom field.

Integration Patterns Determine Data Flow Risk

How does data flow in and out of Shopify?

ERP and inventory systems. Real-time sync vs. batch? Native integration or middleware? What happens when inventory updates fail?
Order management and fulfillment. Where does order data go after purchase? What transformations happen?
Marketing and email platforms. Klaviyo, Attentive, etc., how is customer and event data synced? Through native apps or custom flows?
Custom middleware. Many merchants have Zapier flows, custom AWS Lambda functions, or third-party iPaaS connecting systems. These are often undocumented and fragile.

Map every integration. Identify which are native apps, which are custom, and who maintains them.

Data Structure Complexity Hits Platform Limits

Beyond products and orders, assess:

Customer data and segmentation. Custom metafields on customers? Tags used for segmentation? Loyalty program tiers?
Product data complexity. Variant limits, metafields, product types, custom taxonomies. Large catalogs with complex variant structures hit Shopify's limits.
Content pages and navigation. Blog posts, landing pages, navigation structure. These often need manual migration or custom tooling.
Historical data. How much order history needs to migrate? Are there compliance or reporting requirements?

Organizational Context Shapes Execution Risk

Technical assessment isn't enough. Understand who owns what:

Who manages the store? Internal team, agency, freelancer mix? What's their technical capability?
Who owns integrations? Often the answer is "we're not sure", that's a risk signal.
What documentation exists? If the answer is "none," scope your discovery accordingly.
What's the change history? Recent theme changes, app additions, or integration work that might not be stable yet.

Risk Patterns to Flag Early

The App-Heavy Store

50+ apps installed, many inactive or overlapping. Indicates organic growth without technical governance. Migration will require rationalization before rebuild.

The Script Editor Store

Heavy Script Editor usage for discounts and shipping. Every script needs to be rebuilt as a Shopify Function. This is consistently underestimated in migration scoping.

The Checkout.liquid Store

Significant checkout.liquid customization on Plus. Mandatory migration to Checkout Extensibility means rebuilding checkout logic and UI from scratch.

The Middleware Maze

Multiple integration touchpoints with unclear ownership. Data flows through Zapier, custom APIs, and third-party connectors with no documentation. High risk of breaking something critical.

The Metafield Dependency

Theme and apps heavily dependent on metafields, but no clear metafield schema documentation. Migration requires reverse-engineering data relationships.

Assessment Deliverables That Drive Decisions

A complete Shopify assessment delivers:

App inventory with categorization, risk flags, and migration implications
Theme analysis documenting customization level, metafield usage, and rebuild requirements
Checkout audit covering Script Editor, checkout.liquid, and current extensibility state
Integration map showing all data flows, owners, and technical approaches
Data assessment covering volume, complexity, and migration requirements
Risk register identifying specific technical and organizational risks
Scope recommendations with effort estimates tied to specific findings

Each finding should connect to migration scope and project risk.

How DigitalStack Supports Shopify Assessments

DigitalStack treats platform assessments as structured engagements, not ad hoc audits.

Systems inventory captures apps, integrations, and technical components with structured attributes, categorization, ownership, and risk flags that connect to downstream decisions.

Stakeholder surveys gather input from the people who actually manage the store. Technical teams, marketing, operations, each has context about how systems are used and what's critical.

Objectives tracking connects findings to business goals. A checkout customization isn't just a technical migration item, it's tied to a revenue protection objective that justifies the effort.

Requirement generation translates assessment findings into structured requirements. App dependencies become integration requirements. Checkout customizations become function specifications. Nothing gets lost between discovery and build.

Output generation produces assessment reports and migration scope documents from structured data. Findings stay connected to recommendations, and recommendations stay connected to requirements.

Next Step

If you're running Shopify assessments with spreadsheets and slide decks, you're losing context between what you find and what you recommend.

See how DigitalStack structures platform-specific discovery work, request a demo.