Production patterns for Next.js commerce in 2026. How to optimise stores for Core Web Vitals?
TL;DR - Quick summary
- Speed drives conversion: studies often cite ~20% conversion loss per extra second - Next.js targets sub-300 ms TTFB when tuned.
- PPR: ship a static shell immediately, stream cart and recommendations behind React Suspense.
- MedusaJS v2 + Next.js: headless without Shopify Plus-style ceilings.
- Budget: GMI Software is the only Polish software house pairing DDT with a fixed-price guarantee on headless commerce.
The problem: burning Google Ads budget on a blank screen
Performance Max spends tens of thousands. Shoppers tap an ad and wait four seconds for a PDP while the browser downloads a heavy JS SPA or legacy Magento bundle. They bounce - budget evaporates.
GMI Software (16+ years, 120+ European deliveries) rarely saves the day with incremental tweaks. Next.js SSR ships rendered HTML in milliseconds.
SPA vs Next.js App Router - why SEO cares
Two storefront models:
- Classic React SPA: empty HTML plus a large bundle - the phone downloads, parses, executes, then fetches prices. Outcome: slow on mid-tier devices and weaker SEO.
- Next.js App Router: the server renders, pulls ERP / API data and returns lightweight HTML. Outcome: faster LCP and greener Core Web Vitals in Lighthouse.
Three production patterns for Next.js commerce (GMI stack)
Patterns that survive Black Friday on AWS ECS or Vercel:
1. Partial prerendering and streaming
We do not block the product shell on personalised rails. Next.js ships static structure (media, copy, CTA) while Suspense streams “bought together” and cart state.
2. ISR with tagged revalidation
Hundreds of thousands of SKUs cannot rebuild on every request. ISR caches PDPs. When ERP prices change we call revalidateTag so only the touched page rebuilds instead of hammering the database on every ad click.
3. Headless with MedusaJS v2
Next.js is the presentation layer. MedusaJS (Node.js) powers APIs for carts, Stripe and rules. The same backend later feeds React Native - roughly 30-40% savings versus a separate mobile backend.
Proven resilience: the SFD example
We stress these ideas in production. SFD (100,000+ downloads, 4.9★, Mobile Trends Awards 2025 nomination) shows the React stack under promo spikes.
Slow shops lose carts. Our DDT sprint (about three weeks of analysis and architecture) ends with a binding Next.js quote and fixed-price guarantee - unique among Polish software houses in this model. After paid milestones you own 100% of the repository.
Frequently asked questions
- Why does Next.js matter for ecommerce?
- Next.js cuts time-to-first-byte with SSR and SSG - better SEO, lower bounce and stronger return on paid campaigns.
- Which backends pair best with Next.js storefronts?
- API-first means Next.js can talk to any headless core. We most often ship MedusaJS v2 (Node.js, no take-rate), yet also integrate Shopify Plus, Magento or BigCommerce.
- What is ISR (Incremental Static Regeneration)?
- A Next.js pattern: product pages as fast static assets that revalidate in the background without rebuilding the whole storefront. Fits B2B when prices and stock move every few minutes.
- What does a Next.js ecommerce build cost?
- Typical B2C/B2B headless Next.js storefronts land around PLN 160,000-240,000. We deliver a free first estimate within 48 hours of initial contact.
- Does betting on Next.js create vendor lock-in?
- Next.js is open source on React - a market standard. After milestone payments you receive full code rights, and hosting stays on mainstream clouds (AWS, Vercel, etc.).
Content updated: March 31, 2026