React development company
We build React front ends meant to survive years of contributors: component libraries documented in Storybook, server state handled by TanStack Query, forms validated with Zod, and a clear upgrade path to React 19 and the React Compiler.
- Senior engineers · IST + EST overlap
- NDA on day 1
- 24-hour reply
- Projects shipped
- 50+
- Code ownership
- 100%
- Client rating
- 4.8/5
- First reply
- 24h
Where React projects go right or wrong
Krapton works as a React development company for products whose value lives in the browser: dashboards, editors, internal tools, embeddable widgets and the design systems behind them. React itself is a small library, so most of the engineering sits in what surrounds it, and that is where our React development services concentrate. We separate server state from UI state instead of pushing everything into one global store, choose between TanStack Query, Zustand and Redux Toolkit by the shape of the data, and keep effects out of places where a derived value belongs. Teams still on Create React App, which the React team deprecated in 2025, get their build moved to Vite or to a framework such as Next.js or React Router. Older codebases get a planned climb to React 19, with legacy patterns like string refs and defaultProps on function components removed, and the React Compiler evaluated wherever manual memoization has spread.
React development services
Single-page applications
Data-heavy React SPAs built with Vite, React Router and TanStack Query, using route-level code splitting, optimistic updates and error boundaries placed where a failure should stay contained.
Design systems and component libraries
Accessible component libraries on Radix primitives or React Aria, documented in Storybook, versioned as an internal package and tested for keyboard use, focus handling and visual regressions.
React 19 upgrades
Moves from React 16, 17 or 18 to React 19: createRoot adoption, removal of deprecated APIs, ref-as-prop cleanup, updated @types/react definitions and a staged rollout behind feature flags.
State management cleanup
Untangling global stores that hold server data, replacing hand-written fetch-and-cache code with TanStack Query or RTK Query, and narrowing context providers that re-render entire trees.
Micro-frontends and embeds
React widgets embedded in other sites or legacy pages, and Module Federation setups that let separate teams deploy parts of one interface independently, with shared dependency versions pinned.
Interaction performance tuning
Profiling with React DevTools and the Chrome Performance panel to fix slow INP: virtualizing long lists, deferring work with useTransition and splitting contexts that trigger needless renders.
Why teams choose Krapton for React
Senior engineers, fixed scope, and code you own — the things agencies promise and rarely deliver.
Server state kept separate
Most React codebases that feel fragile treat API data as client state; we let a query cache own fetching, caching and invalidation, leaving stores for genuine interface state.
Fewer effects, fewer bugs
Our engineers follow the React team’s guidance that many useEffect calls are unnecessary, computing derived values during render and handling events in handlers, which removes a common source of loops.
Accessibility in the definition of done
Components ship with keyboard support, visible focus, correct ARIA roles and axe-core checks in CI, because retrofitting accessibility into a finished component library is slow and disruptive.
Framework advice without bias
We will say when plain React with Vite is enough and when Next.js, React Router framework mode or Astro fits better, based on your rendering and search requirements.
How a React project runs with Krapton
01
Codebase and UX audit
We review component structure, state flows, bundle composition and accessibility gaps, and read real-user INP and LCP data before proposing any rewrite.
02
Component contracts
Props, variants and states for shared components are agreed in Storybook with your designers before feature screens are assembled from them.
03
Incremental delivery
Screens ship behind feature flags with React Testing Library tests, Playwright journeys and Chromatic visual diffs attached to every pull request.
04
Release and measure
After release we watch error boundaries in Sentry and interaction timings in field data, then fix the slowest interactions before adding new ones.
The React stack we build with
React development: questions answered
What should a React development company deliver besides components?
An architecture that keeps components cheap to change. A React development company should settle state ownership, data fetching, routing, error handling and testing, and provide a component library with documented variants. Without those, every new screen invents its own patterns and the codebase slows down within a few releases. We hand over Storybook docs, test suites and written reasons for each library choice.
Do we need Next.js, or is plain React enough?
Plain React with Vite is enough when the app sits behind a login and does not depend on search traffic. If public pages must rank or load quickly on a first visit, a framework with server rendering, such as Next.js or React Router in framework mode, is the better base. Many products combine both: a framework for marketing and catalog pages, and a Vite SPA for the signed-in app.
Should we use Redux Toolkit, Zustand or React Context?
Pick by what the state is, not by popularity. Server data belongs in TanStack Query or RTK Query. Small shared interface state fits Zustand or Context, though Context re-renders every consumer whenever its value changes. Redux Toolkit earns its place in large apps with many developers, complex client-side workflows or a need for strict conventions and time-travel debugging.
How hard is upgrading an older React app to React 19?
Moderate for most apps, harder for ones tied to old dependencies. The React APIs change little for code already using hooks and createRoot; friction comes from libraries that relied on removed APIs, outdated type definitions and legacy class patterns. We upgrade to React 18.3 first so deprecation warnings surface, run the official codemods, fix what the warnings reveal, and then move to React 19.
Is the React Compiler worth enabling?
Often yes, once your code follows the Rules of React. The compiler memoizes components and values automatically, which can remove most hand-written useMemo, useCallback and React.memo calls. It skips components that break those rules, so we run its lint rules first, fix the violations, enable it one directory at a time and compare render counts in the Profiler before and after.
Ready to build? Tell us what you have in mind.
Send a short brief and a senior engineer will reply within one business day with next steps — no sales fluff.