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Software Engineering

Frontend Development

The client side of your application, built as real engineering — component architecture, state, accessibility and performance that hold up as the product grows.

Overview

Frontend development is the part of the system your users actually touch: the components, the state, the interactions and the rendering that turn a design and a set of APIs into something a person can use. It is often mistaken for “making it pretty”, and that misunderstanding is where most frontend problems begin. Layout and styling are the visible surface, but the engineering that matters sits underneath — how state is structured, how data flows through the interface, how the thing stays fast and accessible on a phone you have never seen, and whether the next developer can add a feature without breaking three others. That is the work, and it is genuinely hard.

The reason it is hard is that a browser is a hostile environment you do not control. Your code runs on devices and connections you cannot predict, alongside assistive technology, ad blockers, flaky networks and a decade of accumulated browser quirks. State — what the interface currently believes to be true, and how that stays in sync with the server — is where most real bugs live, and it gets harder, not easier, as the application grows. A frontend that felt clean at ten components can become the thing everyone is afraid to touch at two hundred, and that decay is an architectural failure, not an inevitability. We build so it does not happen.

We work primarily in React and Next.js, and in Vue where a team already lives there, always with TypeScript, because on any interface large enough to matter the type system pays for itself many times over in bugs that never ship. We are equally blunt about the trade-off that defines modern frontend: rendering everything in the browser is quick to reach for and quietly expensive. It hurts first-load speed and, unless you use server-side rendering, it can leave your pages looking like an empty shell to search engines. We reach for client-side interactivity where it earns its cost and render on the server where it does not — a decision made per view, not once for the whole app.

Who it’s for — Teams who need the client side of a web application built or rebuilt properly — fast, accessible, maintainable and wired to real APIs — by senior engineers who treat the interface as engineering rather than decoration.

What you get

  • A component architecture with clear boundaries and a sensible state model, built in React, Next.js or Vue with TypeScript throughout, so the codebase stays legible as it grows rather than collapsing into interdependent spaghetti
  • Accessible interfaces built to WCAG — real keyboard navigation, correct focus management, semantic structure and ARIA only where it is actually needed — verified against screen readers rather than signed off from a mock-up
  • A performance budget for Core Web Vitals, held with code-splitting, lazy loading, image and font strategy and disciplined bundle management, measured on mid-range devices and throttled connections
  • Responsive layouts that work from a small phone to a wide desktop, built mobile-first against real breakpoints rather than the two screen sizes on the developer’s desk
  • The API integration layer — data fetching, caching, loading and error states, optimistic updates and retries — so the interface behaves correctly when the network misbehaves, not only on the happy path
  • A design system or component library implemented as reusable, documented, tested components, so the interface stays visually consistent and new screens are assembled rather than reinvented
  • Server-side or static rendering where first-load speed and search visibility matter, so pages arrive fully formed for both users and crawlers instead of as an empty shell that fills in later

What Frontend Development does for you

  • An interface that stays fast under real conditions

    Performance on the frontend is decided by what you ship to the browser and when — bundle size, render strategy, image handling, how much JavaScript runs before the page is usable. We budget those from the start, because clawing speed back out of a slow client-side architecture after launch costs far more than building for it. The result is an interface that stays quick on the mid-range phone your users actually hold, not just the developer’s laptop.

  • Accessibility that widens your audience and lowers your risk

    An interface built to WCAG — proper semantics, keyboard operability, managed focus, sufficient contrast — is usable by more people and exposes you to less legal and reputational risk. Accessibility is cheap when it is designed into the component layer and expensive when it is retrofitted, so we build it in from the first component rather than auditing it on at the end when every fix means unpicking markup.

  • A frontend your team can keep building on

    The real cost of an interface is every change made to it after launch. A clear component architecture and a deliberate state model mean a developer can find the right place to make a change, make it safely, and ship it — instead of being afraid to touch a codebase where everything is entangled with everything else. Maintainability is not a nicety here; it is the difference between a product that keeps moving and one that grinds to a halt.

Why teams choose us for Frontend Development

  • We treat the frontend as engineering, not decoration. The hard parts — state, performance, accessibility and long-term maintainability — get the attention they deserve, rather than being an afterthought to the visual layer.
  • Senior engineers do the work. The people who architect your component and state structure are the people who write it — you are not shown expertise in the pitch and handed juniors for the build.
  • We are honest about rendering trade-offs. Where a client-only single-page app would hurt your search visibility or first-load speed, we say so and use server-side rendering, rather than defaulting to whatever the framework makes easiest.
  • We build on your stack and hand it back clean. Your repository, your accounts, TypeScript throughout, documented components — nothing your own team could not pick up and run without us in the room.

What Frontend Development includes

The concrete pieces of work this covers — scoped to what your problem actually needs.

  • Component architecture in React, Next.js and Vue

    Interfaces structured as composable, single-responsibility components with clear boundaries between what renders, what holds state and what fetches data. Built with TypeScript so the contracts between components are enforced by the compiler rather than by hope, and organised so the codebase stays navigable as it scales past the point where ad-hoc structure falls apart.

  • State management done deliberately

    State is where frontend complexity concentrates, so we treat it as an explicit design decision rather than reaching for a global store by reflex. Local state, server-cache state and genuinely shared client state are different problems with different tools — from a query and caching library for server data to a lightweight store only where it is warranted — and matching each to the right approach is what keeps the interface predictable under change.

  • Accessibility to WCAG

    Semantic HTML first, keyboard operability throughout, focus managed correctly across dynamic content and route changes, and ARIA applied only where native elements cannot do the job. Verified against real assistive technology — screen readers, keyboard-only navigation — because an interface can pass an automated checker and still be unusable to someone who depends on a screen reader.

  • Performance and Core Web Vitals

    Code-splitting and lazy loading so a page ships only the JavaScript it needs, image and font strategy to keep Largest Contentful Paint and layout shift under control, and a bundle kept under a measured budget rather than allowed to creep. We profile on throttled connections and mid-range hardware, because that is where the difference between fast and slow is actually felt.

  • Responsive and cross-device UI

    Layouts built mobile-first against real breakpoints, using modern CSS — flexbox, grid, container queries where they help — that adapt from a narrow phone to a wide desktop and everything between. Tested on real devices and browsers rather than assumed to work from a single desktop viewport.

  • Design systems and component libraries

    A design system implemented as a documented, tested, reusable set of components with consistent tokens for colour, spacing and typography, so screens are assembled from known parts instead of rebuilt each time. Done well this is what keeps a growing product visually coherent and speeds up every future feature; done badly it is a folder of components nobody trusts, so we build it to be used.

Where it fits

  • A design turned into a fast, accessible interface

    You have designs and a set of APIs, and you need them built into a real, production-grade interface — not a rough approximation that drifts from the design and falls apart on a phone. We implement it faithfully, responsively and accessibly, and wire it to the back end so it behaves correctly when the network is slow or an API errors, not only when everything goes right.

  • A design system built or implemented

    You need a consistent component library — either designed with you or implemented from an existing design system — so your product stops looking like several different applications stitched together and your team stops rebuilding the same button for the fifth time. We deliver documented, tested, reusable components that your engineers actually adopt.

  • A slow or inaccessible frontend rescued

    An existing interface that is heavy, sluggish on mobile, or locks out keyboard and screen-reader users. We profile where the time and weight are actually going, fix the render and bundle problems at their source, and bring the interface up to a WCAG standard — rather than papering over symptoms with more configuration.

  • A client-only SPA that search engines cannot see

    A single-page application that renders everything in the browser and, as a result, appears as an empty shell to crawlers and loads slowly on first visit. We migrate the parts that need it to server-side or static rendering — often on Next.js — so the pages arrive fully formed, without throwing away the interactivity the application genuinely needs.

How we approach Frontend Development

We start from the interface’s two hardest questions before we write components: how state is structured, and where each view is rendered. Getting the state model right — what is local, what is server data that should be cached and revalidated, what is genuinely shared across the app — prevents the tangle that makes large frontends unmaintainable, and it is far cheaper to decide up front than to unpick later. The rendering question is just as consequential: which views must arrive fully formed for speed and search visibility, and therefore render on the server, and which are behind a login where client-side rendering is fine. We answer both per view rather than applying one blanket choice.

From there we build the interface as a system of composable, typed components against a performance and accessibility budget agreed at the outset, not bolted on before launch. We integrate with your APIs deliberately — handling loading, error and empty states as first-class cases rather than afterthoughts — and we treat the client as untrusted throughout, because it is. We would rather ship an interface that is slightly less clever but that your team can extend safely for years than an impressive one only its original author dares to touch.

How we deliver a frontend build

We begin by understanding the interface as a whole: the designs, the API contracts it consumes, which views are public and search-facing versus behind authentication, and where the genuine interactivity lives. This is where we decide the rendering strategy per view, agree the Core Web Vitals and accessibility budgets, and settle the state architecture — the decisions that are cheap now and expensive to reverse once components are built on top of them.

Delivery happens in short, reviewable cycles against a running interface, not a single reveal at the end. We build the component foundations and the design-system pieces first, because everything else is assembled from them, and we get real screens in front of you on real devices early so feedback lands while it is still cheap to act on. Loading, error and empty states are built alongside the happy path rather than left as a tidy-up phase that gets cut.

Before handover we run the pass that separates a finished frontend from a demo: accessibility testing against actual screen readers and keyboard-only navigation, a Core Web Vitals audit on throttled connections and mid-range devices, cross-browser and cross-device checks, and a review of how the interface behaves when APIs are slow or failing. Then we hand over documented components and a codebase your own engineers can extend.

How we structure the client

The frontend’s architecture is really two structures: the component tree and the state that flows through it. We keep components small and single-purpose, with a clear separation between presentational components that render, container logic that fetches and coordinates, and shared primitives that come from the design system. That boundary is what lets the interface grow to hundreds of components while staying navigable — the alternative, where data-fetching, business logic and markup are all tangled together in every file, is exactly the entanglement that makes large frontends unmaintainable.

State gets modelled deliberately rather than by reflex. Server data — anything that lives on the back end and is fetched — is treated as a cache to be fetched, revalidated and invalidated, typically through a query library, not copied into a global store where it immediately goes stale. Genuinely client-side shared state gets a lightweight store only where it is warranted, and most state stays local to the component that owns it. Getting this taxonomy right is the single biggest determinant of whether the frontend stays predictable as features accumulate.

Rendering is the third pillar. We decide per view whether it is server-rendered, statically generated or client-rendered, based on whether first-load speed and search visibility matter for that view — because shipping an entire application’s worth of JavaScript to render content that could have arrived as HTML is a cost paid on every visit. TypeScript runs through all of it, so the contracts between components and with your APIs are enforced by the compiler, and the whole thing is built on your stack and accounts with no proprietary layer you have to keep paying for.

Security on the client

The first rule of frontend security is that the client cannot be trusted, because anyone can open the developer tools and change it. Validation, authorisation and any rule that actually protects data must live on the server; the frontend enforces them for user experience, never as the real boundary. We build with that assumption throughout — the interface can hide a button, but it can never be the thing that decides whether an action is allowed. Any team that treats a disabled control as security has already been bypassed.

The most common frontend vulnerability is cross-site scripting, where untrusted content is rendered as executable markup. We avoid it by relying on the framework’s built-in escaping, never reaching for the raw HTML-injection escape hatches without sanitising, and setting a sensible Content Security Policy so that even a mistake has a smaller blast radius. Secrets are the other frequent slip: anything shipped to the browser is public, so API keys and credentials never live in frontend code or environment variables that get bundled — sensitive calls go through a server-side layer that holds the secret and the client never sees it.

Beyond those, we handle the everyday hygiene: tokens stored and transmitted sensibly, dependency scanning so you are not shipping known vulnerabilities in a package deep in the tree, and care with third-party scripts, which run with full access to your page and are a routine source of compromise. None of this is glamorous, and all of it is the difference between an interface that is merely functional and one that is actually safe to put in front of the public.

Signs it’s time

  • Your interface is slow on a normal phone, and users are leaving before it becomes usable, no matter what the back end does
  • The frontend has grown to the point where every change risks breaking something else, and developers have started to fear touching it
  • An accessibility complaint, audit or procurement requirement has made WCAG conformance suddenly urgent
  • Your single-page app renders everything in the browser and barely appears in search, because crawlers see an empty shell

How we work and hand over

We work in the open and in short cycles, with a running interface you can click through early rather than a status report describing one. A senior engineer can explain any decision in plain terms — why a view renders on the server, why a piece of state lives where it does, why a component is built the way it is — and we surface trade-offs as they arise: the performance cost of a heavy animation, the maintainability cost of a shortcut, the accessibility implication of a particular interaction. You make informed calls rather than discovering the consequences after launch.

Handover is a deliverable, not a courtesy. You get the code in your own repository, TypeScript throughout, a documented component library, and a walkthrough of the architecture and state model thorough enough that your own developers can extend the interface without us. There is no proprietary layer and nothing you would have to unpick to move to another team. If you want us to stay on, we are glad to — but that should be a choice you make freely, never a dependency we engineered you into.

Technologies we build it with

Chosen per problem, not per fashion — this is the stack we most often reach for on this work.

How we deliver

  1. 01

    Discover

    We map the system, the constraints and the business it serves — including the parts nobody documented.

    Architecture brief

  2. 02

    Architect

    Decisions get made, written down and defended before a line of production code exists.

    Decision records

  3. 03

    Build

    Short cycles against working software. You see progress in the product, not in a status deck.

    Shipping increments

  4. 04

    Operate

    Monitoring, incident response and iteration. The system is alive, so the engagement is too.

    Runbooks & SLOs

What changes

  • An interface that stays fast

    Core Web Vitals held to a measured budget on mid-range devices, so speed is a property of how the client is built rather than a hope that survives until the next feature.

  • Accessible to everyone who needs it

    A WCAG-conformant interface verified against real screen readers and keyboard navigation, widening who can use your product and lowering your legal exposure.

  • A frontend that scales without seizing up

    A clear component and state architecture, in TypeScript, that lets your team keep adding features safely instead of slowing to a crawl as the codebase grows.

Industries we serve

Domain knowledge changes what gets built. A few of the sectors we know before the first meeting.

How pricing works

  • The number of distinct views and their complexity is the primary driver: a handful of mostly-static screens and a data-dense application with dozens of interactive, stateful views are separated by a large amount of engineering, so we cost them separately rather than averaging across the interface.
  • How much genuine interactivity and shared state the interface carries matters more than raw page count — a form-heavy, real-time or highly stateful application demands far more frontend engineering than the same number of largely static views.
  • Whether a design system exists shapes the figure in both directions: implementing an established, well-documented system is faster, while designing and building one from scratch is real up-front work that pays back across every later screen.
  • Accessibility and performance targets affect scope honestly — bringing an interface to a specific WCAG conformance level or a strict Core Web Vitals budget is engineering effort we account for rather than pretending it is free.

Typical timeline

  1. 01

    Architecture and setup

    We settle the component and state architecture, decide rendering per view, agree the performance and accessibility budgets, and stand up the project with TypeScript, tooling and the design-system foundations.

  2. 02

    Component foundations

    The shared primitives and design-system components are built and documented first, because every screen is assembled from them, and reviewed early on real devices.

  3. 03

    Views and integration

    Screens are built in short cycles against your APIs, with loading, error and empty states handled alongside the happy path, and feedback gathered on a running interface.

  4. 04

    Hardening and handover

    Accessibility testing against real assistive tech, a Core Web Vitals audit on throttled connections, cross-browser checks, then handover of a documented, maintainable codebase.

Why teams choose us for Frontend Development

  • Frontend as engineering, not decoration

    We give the genuinely hard parts — state, performance, accessibility, maintainability — the attention they need, rather than treating the interface as a styling exercise laid over someone else’s real work.

  • Senior engineers, no bait-and-switch

    The people who design your component and state architecture are the people who build it. You are not sold seniority in the pitch and handed a junior team once the contract is signed.

  • Honest about rendering and complexity

    Where a client-only SPA would wreck your search visibility or first-load speed, we say so and use server-side rendering. Where a lighter approach beats a heavier one, we tell you rather than reaching for the most complex option by default.

  • A codebase you own and can run

    TypeScript throughout, documented components, your repository and accounts, and a handover thorough enough that your team can extend it without us — no proprietary layer and no engineered-in dependency.

How to engage us

Three ways to work with us on this — chosen to fit the problem, not our margin.

Related services

Part of Custom Software Development. Other work we do alongside this.

Common questions

Isn’t frontend just styling and making things look nice?

The styling is the visible part, but it is not where the difficulty is. The hard engineering on the frontend is state — keeping what the interface believes in sync with the server — along with performance on devices you do not control, accessibility for people using assistive technology, and keeping the codebase maintainable as it grows from ten components to hundreds. Those problems get harder as the application scales, and getting them wrong is what turns a frontend into the thing everyone is afraid to touch. Treating it as decoration is precisely how projects end up there.

How is this different from your Backend and Web Development services?

Frontend Development is the client side specifically — the components, state, rendering and interactions that run in the browser, wired to APIs someone else provides. Backend Development is the server side: the APIs, data storage, authentication and business logic behind them. Web Development is the broad service that spans both plus content sites and simpler builds. If you have designs and APIs and need the interface built, this is the service. If you need the whole thing, we scope frontend and backend together — and we will say honestly which you actually need.

Do we need server-side rendering, or is a single-page app fine?

It depends on the view. A client-only single-page app is fine behind a login, where search visibility is irrelevant and users accept a short initial load in exchange for a fast, app-like experience afterwards. It is a poor choice for public, search-facing pages, because crawlers and the first visit see an empty shell that only fills in once the JavaScript runs — which hurts both SEO and perceived speed. We decide per view: server-side or static rendering where first load and search matter, client rendering where the interactivity justifies it.

Which framework do you use — React, Next.js or Vue?

We work primarily in React and Next.js, and in Vue where your team already lives there, always with TypeScript. Next.js is our usual default when a project needs server-side rendering, routing and a production build system out of the box, which most application frontends do. If you already have a codebase in one of these, we work in it rather than pushing a rewrite for its own sake. The framework should follow the requirement and your team’s existing skills, not a preference we impose.

Can you take over and fix our existing frontend rather than rebuilding it?

Usually, yes, and it is often the better call. We start by profiling where the real problems are — the render strategy, the bundle size, the state tangle, the accessibility gaps — because the honest diagnosis frequently differs from the assumed one. From there we fix issues at their source and improve the architecture incrementally, so the interface keeps working while it gets better. A full rebuild is sometimes genuinely warranted, but it is a decision we make with you on the evidence, not a reflex to justify starting over.

Let’s talk about Frontend Development.

Tell us what you’re building or fixing. A senior engineer reads every enquiry and replies within a business day.

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