Replatforming to BigCommerce Catalyst gives mid-market operators access to headless frontend architecture, Next.js performance capabilities, and the integration flexibility that Stencil-based storefronts can't provide. Getting there requires a structured migration program — not just a technical lift-and-shift.
The merchants who execute Catalyst migrations well treat it as a program with defined phases, clear acceptance criteria, and deliberate SEO continuity planning. Those who treat it as a development project frequently discover the gaps in that approach after go-live.
Here's a phase-by-phase roadmap.
Phase 1: Migration Planning
Before selecting tools or writing code, audit the current state completely:
- Frontend inventory — catalog of all current templates, custom components, third-party scripts, and storefront customizations that need to be accounted for in the new build
- Integration inventory — all current connections between BigCommerce and external systems (ERP, CRM, payment processors, shipping providers, marketing tools) with documentation of how each integration is implemented
- Data inventory — products, categories, customers, order history, pricing rules, promotions — understanding data volume and complexity before migration begins
- Performance baseline — current Lighthouse scores, Core Web Vitals, and traffic/conversion metrics that the migration should improve, not degrade
The planning phase output is a complete picture of what exists today and a defined scope for what the migration needs to deliver.
Phase 2: Strategy and Architecture
Define the migration approach before any build work begins:
- Headless vs. hybrid deployment — full headless (Catalyst for all storefronts) or phased (Catalyst for key pages while Stencil continues for others during transition)
- Frontend architecture decisions — component structure, state management, rendering strategy (SSR vs. SSG per page type), hosting and deployment pipeline
- Integration strategy — which integrations rebuild through GraphQL, which use REST, which require middleware
- Hosting infrastructure — Vercel, Netlify, or custom edge deployment; CDN configuration; environment management
Phase 3: Data and Integration Migration
Transfer and validate:
- Products, categories, variants, images, metadata
- Customer accounts and order history
- Pricing rules, promotions, and discount structures
- Reconnect ERP, CRM, payment, and shipping integrations through the new API architecture
Validate each data category against the source system before proceeding — data issues discovered post-launch are significantly more expensive to fix.
Phase 4: Frontend Rebuild
The Catalyst build phase involves:
- Component development in React against the BigCommerce GraphQL Storefront API
- Performance optimization — image handling, code splitting, lazy loading, Core Web Vitals targets
- Accessibility compliance — semantic HTML, ARIA attributes, keyboard navigation, color contrast
- Visual editor configuration through Makeswift for marketing team autonomy
- Mobile-first responsive implementation
Performance benchmarking should happen continuously during build, not only at the end.
Phase 5: SEO Migration
SEO continuity is where Catalyst migrations most commonly fail when executed without structure:
- URL mapping — every URL that changes needs a 301 redirect configured before launch
- Metadata preservation — page titles, meta descriptions, structured data, and canonical tags carried forward accurately
- XML sitemap regeneration — updated to reflect the new URL structure
- Pre-launch SEO audit — validate that all redirects work, that canonical tags are correct, and that no unintended noindex tags are present
- Search Console monitoring — watch for coverage errors and crawl issues in the days following launch
Phase 6: Testing, Launch, and Optimization
Before go-live:
- Load testing at expected peak traffic volumes
- Full transactional testing (add to cart, checkout, payment, order confirmation, account management)
- Cross-browser and cross-device validation
- Lighthouse score validation against targets
- Rollback plan confirmed and tested
Consider a soft launch — limited traffic redirection before full cutover — for operations where any launch risk is unacceptable.
Post-launch, budget for a two to four week optimization window before declaring the migration complete.
Arizon Digital has executed BigCommerce Catalyst migrations for mid-market operators across retail, B2B, and distribution. Talk to us about what a migration program would look like for your specific storefront complexity and integration requirements.