When your storefront lives inside Liquid or legacy templates, the theme eventually becomes the constraint: changes take longer, the app/customization stack gets fragile, and performance slowly drifts down - until it starts hurting conversion. Headless can fix that, but it’s not a “free upgrade”. It adds engineering surface area, so I validate the business case first: traffic, roadmap, support cost (TCO), SEO risk, and what can realistically be covered by the APIs. In a composable setup, Next.js is the product layer, while Shopify/Magento remain the commerce engine. Data flows through Shopify Storefront API / Customer Account API and Magento GraphQL, and content, search, analytics, and loyalty are integrated as services behind clear contracts. Before we commit, I also compare the practical alternatives (Hydrogen/Oxygen for Shopify, PWA Studio/Hyvä/Alokai for Magento) to pick the lowest-risk, best-TCO path for your constraints and budget.
What You Actually Get
Predictable Performance (Measured in RUM, Not Scores)
We ship a Next.js 16 storefront (PPR/streaming) with CDN edge caching and performance budgets. We track Core Web Vitals (LCP/INP/CLS) on real users via RUM - and put guardrails in place to prevent regressions.
Shipping Changes Without Theme Landmines
We decouple UX from theme constraints and brittle app/theme customizations. That means fewer regressions, simpler QA, and a safer release process. Marketing can build landing pages within agreed blocks without creating an endless engineering queue.
API Contracts Instead of Hidden Coupling
We build around explicit data contracts: Shopify Storefront API / Customer Account API and Magento GraphQL. This removes “mystery dependencies”, makes integrations repeatable, and reduces long-term support cost - instead of constantly chasing side effects.
A Governed Composable Stack (Flexibility Without the Maintenance Tax)
We integrate CMS, search, analytics, and loyalty as composable services and lock in the rules: data ownership, caching, and observability (logs/RUM). And if headless isn’t the best option, I’ll say it and recommend a more rational path (Hydrogen/Oxygen, PWA Studio, Hyvä, Alokai) for your goals and budget.
Migration Plan
- 1
Audit - baseline (performance, SEO, conversion), API gap check, and KPI/ROI model. If it won’t pay off, I’ll say so before we build.
- 2
Architecture - data contracts, caching strategy, content model, and a phased rollout + rollback plan (safe path).
- 3
Build - Next.js 16 storefront + UI system + analytics instrumentation (funnel/events/RUM) and third-party script governance.
- 4
Launch & Operate - zero-downtime deployment, canary rollout/feature flags, monitoring and regression protection, post-launch optimization.