React Development Company for Modern SPAs

Server Components that eliminate client-side JavaScript. Streaming SSR that doesn't block render. TTI under 1 s and zero hydration errors.

Architecture Audit View Technologies
  • <100ms FCP (First Contentful Paint)
  • 0 Hydration Errors
How we build: requirements, architecture, reviewed code, reversible deployment, measured performance and evolution with your team Every metric sets the next iteration 01 · Requirements What the businessneeds 02 · Architecture Documenteddecisions 03 · Code Reviewed andtested 04 · Deployment Automated andreversible 05 · Performance Core Web Vitals inthe green 06 · Evolution Your team asks, wedeliver
  1. 01 · Requirements What the business needs
  2. 02 · Architecture Documented decisions
  3. 03 · Code Reviewed and tested
  4. 04 · Deployment Automated and reversible
  5. 05 · Performance Core Web Vitals in the green
  6. 06 · Evolution Your team asks, we deliver
  7. Every metric sets the next iteration
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In numbers

Performance Guarantees

Measured metrics. Not promises.

  • <1s TTI Time to Interactive on 4G
  • <50KB JS Bundle Initial load (gzipped)
  • 100 Lighthouse Performance score
  • 15+ Years of Experience Since 2009

Definition

Why Does Hydration Matter?

Hydration is the process where React "wakes up" static HTML sent by the server. Poorly optimized hydration blocks the main thread, causes layout shifts, and turns your app into a slideshow. Server Components eliminate hydration for components that don't need interactivity.

70% of React applications in production suffer from over-hydration: they send JavaScript for components that will never be interactive. With RSC + Selective Hydration, we only hydrate what's necessary. JavaScript bundle shrinks 40-60%. TTI improves proportionally. Ideal for consuming Node.js or Python APIs without penalizing the client.

What's included

Service Deliverables

What you receive. No ambiguity.

  • Next.js architecture with App Router and RSC
  • Documented design system in Storybook
  • TypeScript strict with zero any
  • E2E testing with Playwright
  • CI/CD configured (GitHub Actions)
  • Training for your development team

Summary

Executive Summary

For Management.

React development generates ROI through conversion improvement: each second less of load time equals +7% conversion. Typical project of 8-14 weeks depending on complexity.

Requirement: team with basic JavaScript knowledge. Main risk: learning curve if migrating from another framework. The code is yours from day one, with complete documentation.

  • +7% Conversion/Second
  • 8-14 wks Typical Project
  • 100% Code Yours

For the CTO

Technical Summary

For the CTO.

Base stack: Next.js App Router with React Server Components. State management with Zustand + TanStack Query. TypeScript strict mode mandatory.

Testing with Vitest (unit) + Playwright (E2E). Monorepo with Turborepo if applicable. Deploy on Vercel or own infrastructure (Docker) with servers in Europe.

Technologies

  • Next.js
  • React 19
  • TypeScript
  • Zustand
  • TanStack Query
  • Playwright
  • Turborepo
  • React Server Components for zero unnecessary JS
  • Streaming SSR with Suspense boundaries
  • Initial bundle <50KB gzipped

Who it is for

Is It For You?

React is for complex, interactive interfaces.

Who it's for

  • Teams building complex, interactive web applications.
  • Projects with strict performance requirements (Core Web Vitals).
  • Organizations with established JavaScript/TypeScript ecosystem.
  • SaaS products with rich interfaces and complex state.
  • E-commerce where TTI directly impacts conversion.

Who it's not for

  • Static content sites where Astro or plain HTML suffices.
  • Small-scope projects where a lighter framework is sufficient.
  • Teams without experienced JavaScript developers (extra training required).
  • MVPs where development speed trumps performance requirements.
  • Simple corporate websites without complex interactivity.

Key points

Architectures We Implement

Patterns for specific scenarios.

  1. 01

    Streaming SSR + Suspense

    Server sends HTML progressively while resolving data. Suspense boundaries allow UI parts to render before others. TTFB < 100ms even with slow queries.

  2. 02

    Partial Pre-rendering (PPR)

    Static shell cached on CDN + dynamic slots resolved at request time. Best of static and dynamic rendering, with Next.js.

  3. 03

    Islands Architecture

    Static content by default, interactive islands where needed. Zero JavaScript until user interacts. Ideal for content-heavy sites with critical SEO.

  4. 04

    Monorepo With Design System

    Turborepo + shared packages. UI library in Storybook. Shared types between frontend and backend. One change in design system updates all apps.

How we work

Development Process

From Figma to production without improvisation.

  1. 01

    ADRs (Architecture Decision Records)

    We document every technical decision: rendering strategy, state management, data fetching patterns. Version-controlled ADRs in the repo.

    Sprint 0
  2. 02

    Component-Driven Development

    Components in isolation with Storybook. Props typed with Zod. Visual regression tests with Chromatic. Zero side effects.

    Sprint 1-3
  3. 03

    Integration and Performance

    Data layer with TanStack Query. Optimistic updates. Prefetching. Bundle analysis on every PR. Performance budget enforced in CI.

    Sprint 4-5
  4. 04

    E2E and Deployment

    Playwright tests in CI. Preview deployments on Vercel. Feature flags for gradual rollout. Tracking with Vercel Analytics + Sentry.

    Sprint 6

Risks and how we cover them

Risks and Mitigation

Transparency about what can go wrong.

  1. 01

    Memory leaks

    Mitigation

    WeakRefs, AbortControllers, profiling with Chrome DevTools on every release. Strict cleanup patterns.

  2. 02

    Vercel dependency

    Mitigation

    Docker as fallback, documented self-hosting, portable architecture without vendor lock-in.

  3. 03

    Learning curve

    Mitigation

    Training included, pair programming, exhaustive documentation for your team.

  4. 04

    Over-engineering

    Mitigation

    ADRs with justification, architecture reviews, YAGNI principle enforced on every decision.

Technologies

Technology Stack

Audited dependencies. Zero unnecessary code.

  • Next.js App Router
  • React 19
  • TypeScript strict
  • Zustand
  • TanStack Query v5
  • Tailwind CSS
  • shadcn/ui
  • Radix Primitives
  • Framer Motion
  • Zod
  • Vitest
  • Playwright
  • Storybook
  • Turbopack

Why

Memory Leaks: The Silent Killer

Your app loses 10MB every minute. And you don't know it.

Uncleaned event listeners. Uncancelled subscriptions. Closures retaining references. 80% of React apps have memory leaks that progressively degrade performance. We use WeakRefs, AbortControllers, and strict cleanup patterns. Profiling with Chrome DevTools on every release.

hooks/useAbortableFetch.ts
// Anti-leak pattern with AbortController
export function useAbortableFetch<T>(url: string) {
const [data, setData] = useState<T | null>(null);
useEffect(() => {
const controller = new AbortController();
fetch(url, { signal: controller.signal })
.then(r => r.json()).then(setData);
return () => controller.abort();
}, [url]);
return data;
}
  • 0 Leaks
  • 100% Cleanup
  • Stable Heap

The proof

Enterprise React Specialists

We're not an agency that "sets up WordPress". We've been building high-performance web applications for 15 years. React since 2015, Next.js since its first version. Nexo, our own management platform, runs a React front-end (Inertia over Laravel): we are our own first client. See the case study.

  • 15+ Years of Experience
  • 100+ Lighthouse Score
  • 75+ Bundle Reduction vs. Average
  • 100+ Fixed-Rate Projects

FAQ

Technical Questions

What Engineering Leads ask.

Why Next.js and not Remix or Astro?

Next.js has the most mature ecosystem, best Vercel support, and 90% of job postings ask for Next.js. Remix excels for mutation-heavy apps. Astro for content sites with minimal JS. We choose based on the case, but Next.js is the safe default for enterprise projects. If your team prefers Vue, we also offer Vue.js development.

How do you handle global state?

Zustand for simple client state (~2KB). TanStack Query for server state (cache, revalidation, optimistic updates). Context only for theme/locale. Redux only if the project already uses it. The trend is to minimize global state.

React 19 in production?

Yes. React 19 is stable and we use it in production: Actions, useOptimistic and the useTransition improvements. Nothing experimental in production: canary features wait until they stabilize. Gradual upgrades with codemods.

What's your stance on CSS-in-JS?

Tailwind CSS. Runtime CSS-in-JS (styled-components, Emotion) adds ~12KB and penalizes hydration. Tailwind is zero-runtime, tree-shakeable, and the de facto standard. For complex components, CSS Modules.

How do you connect with Node.js or Python backends?

For Node.js: tRPC for end-to-end type safety, or REST/GraphQL with generated types. For Python FastAPI: OpenAPI spec with automatic typed client generation. If your backend is PHP, we work with Laravel and Inertia, as we do in Nexo. Data flows with synchronized types and zero runtime surprises.

What are the risks of migrating to React/Next.js?

Learning curve if coming from Vue/Angular. Possible Vercel dependency (mitigatable with Docker). Incremental migration with Module Federation or microfrontends. We train teams during transition. Rollback plan always documented.

Do you also build the mobile app?

Yes. With React Native development we share logic, types and team between web and mobile. One TypeScript stack end to end.

Do you work with international companies?

Yes, we're a React agency with 15+ years of experience. We work with clients across Europe and the Americas. Video conference meetings available.

What if it doesn't work?

The code is yours from day one. If you're not satisfied, you can hire another team. No lock-in. We document everything to facilitate transition if necessary.

Next step

Does Your Web Feel Slow?

Free Core Web Vitals audit. We identify exactly which script is blocking your main thread. No commitment.

Request Audit
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  • Response in 24h
  • Custom proposal
Last updated: July 2026

Let's talk.

Initial technical consultation

AI, security and performance. Diagnosis with phased proposal.

  • NDA available
  • Response <24h
  • Phased proposal

Your first meeting is with a Solutions Architect, not a salesperson.

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