--- title: "Frontend development" description: "React and Next.js interfaces with accessible components, design systems and performance work that holds up on real devices and connections." canonical: "https://juhenza.com/solutions/frontend-development" last-updated: 2026-10-15 --- # Frontend development > React and Next.js interfaces with accessible components, design systems and performance work that holds up on real devices and connections. ## Interfaces built to be trusted. The frontend is where your product is judged. We engineer React and Next.js interfaces with the component discipline, accessibility and performance work that keep them dependable as they grow. ## Fit For teams building a new interface, rescuing a screen that has become hard to change, or standardising a growing UI into a system. ## Scope - **React & Next.js applications:** Application interfaces with deliberate rendering and data-loading choices — server-rendered pages where discovery matters, interactive clients where the task needs it. - **Design systems & component libraries:** Reusable, documented components with consistent states — hover, focus, disabled, error — so new screens extend the system instead of diverging from it. - **Accessibility engineering:** Keyboard operation, visible focus, labelled controls, sensible landmarks and reduced-motion support verified as part of the work, not appended to it. - **Frontend performance:** Bundle discipline, caching and loading behaviour measured on mid-range phones and average connections — the devices your users actually hold. ## Process 1. **Map journeys and states:** Agree the tasks, roles, empty states and error paths before writing components. 2. **Build the system, then screens:** Create components with their states, then compose screens; review in the browser at every step. 3. **Verify with real constraints:** Check keyboard, touch, slow networks and content of awkward length; document what was tested. ## Examples ### A new product interface - Challenge: A backend exists, but the screens are inconsistent, slow and hard to use on phones. - Approach: Define the core journeys and their states first, build a small component system, then rebuild the screens against it with keyboard and touch checks. - Deliverable: A consistent, accessible interface with a component library and documented patterns. ### A legacy UI refactor - Challenge: Every change to one screen breaks another; new features take weeks. - Approach: Introduce structure incrementally — shared components, typed data contracts, tests around critical flows — while keeping the product shippable. - Deliverable: A modularised frontend with regression coverage and a refactor roadmap. ### A design-to-code system - Challenge: Designs and code drift apart, so every release re-litigates spacing, type and colour. - Approach: Turn the design decisions into tokens and components, and document how new UI joins the system. - Deliverable: A tokenised component library with usage notes for designers and engineers. ## FAQ ### Do you work from our existing designs? Yes. Figma designs or an existing product are the starting point. Where designs omit states — loading, empty, error — we surface those gaps early, because they are where interfaces actually fail. ### React, Next.js — what about other frameworks? Jainil's experience is deepest in React, Next.js, TypeScript and Tailwind CSS. A different stack can be discussed when your existing system requires it, with maintenance realities stated plainly. ### Is accessibility included or extra? Included. Keyboard operation, focus visibility and labelled controls are engineering requirements, not a separate phase. Full audits against specific standards can be scoped separately. ## Reference architecture A reference frontend structure. The component system and the screens it composes are built and verified as separate disciplines. ### Foundation Design tokens → Component library Give every screen the same type, spacing, colour and interactive states, so the product stays coherent as it grows. Review: Check hover, focus, disabled and error states exist for every component, and that new UI cannot bypass the system. ### Screens Journeys & layouts → Data loading Compose components into journeys that load the right data with deliberate rendering and caching choices. Review: Test each journey with empty records, long content, slow networks and keyboard-only use. ### Verification Accessibility checks → Performance budget Keep the interface usable for keyboard, screen-reader and low-powered-device users as changes ship. Review: Re-verify focus order, landmarks and load behaviour after significant changes, not only at launch. Illustrative planning model; scope and deliverables are agreed per project. ## Technology choices One system, verified states ### Core React · Next.js · TypeScript · Tailwind CSS Choose rendering and state patterns around each journey's discovery, interactivity and data needs. ### System Design tokens · Component library · Story documentation Encode type, spacing, colour and component states once, so every new screen inherits them. ### Checks Keyboard & screen-reader passes · Performance budgets Verify accessibility and load behaviour on mid-range devices as part of the definition of done. ## Quality checks before handover ### Every state designed Confirm loading, empty, error, disabled and success states exist for each component and journey. ### Keyboard & focus Operate every journey with the keyboard alone; check focus visibility, order and trap-free dialogs. ### Performance on real devices Measure load and interaction on a mid-range phone and an average connection, against the agreed budget. ## Preparing for a project Bring the designs or the live product, the journeys that matter most, known pain points and any browser or device constraints your users have. 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