Multi-tenant SaaS
Subdomain or path-based tenancy via middleware, Postgres + Drizzle or Prisma with row-level security, Auth.js 5 or Clerk for auth, Stripe billing with usage metering, and audit logs ready for SOC 2.
Services
Next.js Development Company for Production Web Apps
Senior Next.js engineering for US & EU SaaS, commerce, and content platforms. We ship on Next.js 15 App Router with React Server Components, Server Actions, edge middleware, and Vercel or Cloudflare hosting — with SOC 2-ready observability, strict CSP, GDPR-aligned data residency, and Core Web Vitals as engineering SLOs. Dedicated teams from 12,000 EUR/month per engineer slot; fixed-scope project sprints from 25,000 EUR.
Next.js is no longer a frontend framework — it is a full-stack platform with rendering, routing, caching, mutations, middleware, and edge runtime baked in. That power is the reason teams pick it, and the reason most teams get it wrong on the first try. We have shipped Next.js to production since the Pages Router days, run six full App Router migrations in 2025, and operate apps in single-region Frankfurt, multi-region edge, and self-hosted standalone configurations. Whether you need a greenfield SaaS launched in eight weeks, a headless commerce storefront connected to Shopify or Medusa, or a Pages-to-App migration that does not blow up your SEO, we bring senior engineers who have made the mistakes already.
What we build with Next.js
Headless commerce storefronts
Shopify Hydrogen, Medusa 2, commercetools, or BigCommerce backends fronted by Next.js with ISR for catalogue pages, Server Actions for cart mutations, and edge caching for sub-100 ms LCP.
Content & marketing sites
Sanity, Contentful, Storyblok, or Payload CMS wired to App Router with on-demand revalidation, draft-mode previews, JSON-LD per route, and editorial workflows your marketing team can actually use.
Pages-to-App migrations
Route-by-route cutover behind a feature flag, co-existing router tables, SEO-safe redirects, and zero data-loss on getStaticProps payloads. Typical mid-sized SaaS migrates in 6 to 10 weeks.
Edge & middleware logic
A/B testing at the edge, geo-routing for compliance, bot defence, header rewrites, and CSP nonce injection in middleware.ts — running on the Vercel Edge Runtime or Cloudflare Workers.
SEO & Web Vitals turnarounds
Full Metadata API coverage, sitemap.ts and robots.ts, structured data audits, INP-focused hydration fixes, and Lighthouse CI budgets that block PRs when budgets regress.
Next.js stack we ship in production
Next.js 15 App Router
React 19
React Server Components
Server Actions
TypeScript 5.6
Turbopack
Edge Runtime
Middleware
Vercel
Cloudflare Pages
AWS ECS standalone
Hetzner
Drizzle ORM
Prisma 5
Postgres
Neon / Supabase
Auth.js 5
Clerk
WorkOS
Stripe
Lago
Shopify Hydrogen
Medusa 2
Sanity
Contentful
Payload CMS
Tailwind 4
Radix UI
next-safe-action
Playwright
How a Next.js engagement runs
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01
Discovery & hosting choice
Week 1: hosting trade-off (Vercel vs Cloudflare vs self-host), rendering strategy per route, data-residency decision for GDPR, and a baseline RUM and Lighthouse report.
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02
Architecture & foundations
Weeks 2–3: App Router layout tree, Server Action layer with typed authz, CSP middleware, Drizzle schema, auth wiring, preview deploys, GitHub Actions CI with Lighthouse budgets.
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03
Build in 2-week sprints
Senior engineers ship features behind feature flags, daily PR review, weekly demo, every PR gets a preview URL with seeded data, every merge to main auto-deploys to staging.
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04
Handover & runbook
Ops runbook, on-call rota, observability dashboards (Sentry + Vercel Analytics or Datadog), ADRs in the repo, onboarding video for your engineers, 30-day support tail.
Engagement models
Dedicated team
Long-term Next.js squad: senior full-stack engineers, tech lead, QA, design-system specialist. Your Jira, your standup, your release calendar. From 12,000 EUR/month per engineer slot.
Project sprint
Fixed-scope, fixed-price: greenfield MVP, headless commerce storefront, Pages-to-App migration, or marketing-site rebuild. 4 to 12 weeks. From 25,000 EUR per sprint.
Staff augmentation
Single senior Next.js engineer plugged into your team for 3–12 months. Your stack, your PR review, your on-call. CET hours with US overlap. From 9,500 EUR/month per engineer.
All engagements include NDA, GDPR DPA, IP assignment, EU-based payroll, and EU data-residency by default. No third-country subprocessors without written approval.
Related work
PropTech · Marketplace
ANT
Property marketplace web platform with listing CMS, search and B2B admin console for US and EU operators.
Manufacturing · E-commerce
REHAU
B2B e-commerce and product configurator for a global polymer manufacturer with multi-region pricing, stock and dealer workflows.
LegalTech · Mobile · CRM
Signatory Pro
Native iOS and Android e-signature clients with a Symfony + React CRM for a cross-border law firm — KYC onboarding and a defensible evidence trail for US & EU matters.
Why US & EU teams pick YuSMP for Next.js
GDPR-aligned · ISO 27001 ready · SOC 2 Type II in progress
App Router specialists
Six App Router migrations shipped in 2025, dozens of greenfield App Router products in production. We have already hit the sharp edges — cache invalidation, parallel routes, streaming — and documented the answers.
Hosting-agnostic
Vercel, Cloudflare Pages, AWS ECS standalone, Hetzner — we benchmark all four at kickoff and pick what fits your data-residency, cost, and velocity constraints. No vendor cargo culting.
Compliance-ready by default
EU-region hosting, signed GDPR DPAs, strict CSP with nonce middleware, audit-log baked into Server Actions, and VPAT-ready accessibility for US federal and EU public-sector procurement.
Engineers bill in EUR through an EU entity, work CET hours with 4-hour US East-Coast overlap, and write English-only async-first documentation on Linear, Slack, and Loom.
Frequently asked questions
Do you build on the App Router or the legacy Pages Router?
All greenfield work is on Next.js 15 App Router with React 19, React Server Components, and Server Actions. Pages Router is in maintenance mode and we only touch it for short-term patches on existing apps. We have run six full Pages-to-App migrations in 2025; the typical effort for a mid-sized SaaS is 6 to 10 weeks behind feature flags, with a parallel route table while we cut over. We never recommend a big-bang rewrite — route-by-route migration with co-existing routers is always faster and safer.
Where do you host Next.js apps for US and EU clients?
Three defaults. Vercel for fast-growth SaaS where developer velocity outweighs vendor lock-in — we pick Frankfurt or Dublin regions for EU data residency. Cloudflare Pages with the next-on-pages adapter for cost-sensitive global edge, with Workers KV and D1 for low-latency storage. Self-hosted on AWS ECS or Hetzner with the standalone output, behind CloudFront or BunnyCDN, when the client has strict data-residency or budget constraints. We benchmark all three at the start and document trade-offs in writing.
How do you use Server Components and Server Actions without leaking secrets?
Strictly. We mark server-only modules with the server-only package so accidental client imports fail at build time. Environment variables are split into NEXT_PUBLIC_ for client and unprefixed for server, with a Zod-validated env schema at startup. Server Actions are always wrapped in a typed authz check (next-safe-action 7.x or Zod-validated input + permission guard) and never trust the calling component. We run a CSP with nonce-based script-src in strict mode, enabled via middleware.ts, which catches the majority of accidental inline-script regressions.
How do you handle SEO and Core Web Vitals on Next.js?
Next.js gives you the tools but does not write them for you. We ship full Metadata API coverage with generateMetadata per route, JSON-LD via app-level injection (Organization, Product, Article, BreadcrumbList, FAQPage), sitemap.ts and robots.ts at the app root, ISR or on-demand revalidation for content updates, and image pipelines via the next/image component with sharp 0.33+. Web Vitals are measured via web-vitals 4.x posting to Vercel Analytics or a custom RUM endpoint, with Lighthouse CI budgets gating PRs in GitHub Actions.
Can you build commerce, multi-tenant SaaS, and content sites on the same stack?
Yes, but with different sub-patterns. Commerce uses Next.js + headless commerce backends (Shopify Hydrogen, Medusa 2, commercetools, BigCommerce) with ISR for catalog pages and Server Actions for cart mutations. Multi-tenant SaaS uses subdomain or path-based middleware routing with database-scoped tenancy on Postgres + Drizzle or Prisma. Content sites pair Next.js with Sanity, Contentful, Storyblok, or Payload CMS for editorial workflows. All three patterns share the same App Router, same auth (Auth.js 5 / Clerk / WorkOS), and same observability.
What does a Next.js engagement cost and how is it structured?
Dedicated team from 12,000 EUR/month per senior engineer slot, with a standard SaaS squad (3 Next.js engineers, 1 design-system lead, 1 QA, 1 tech lead) running about 38,000 EUR/month. Project sprints from 25,000 EUR for 4-week fixed-scope builds: greenfield MVP, Pages-to-App migration, headless-commerce storefront, or marketing-site rebuild. All engagements include EU-based engineers on CET hours with a 4-hour US East-Coast overlap, signed GDPR DPAs, IP assignment, and weekly Friday demos.