We see it all the time: a design in Figma looks perfect, but after implementation on mobile everything breaks, Lighthouse reports CLS of 0.5+, and the SEO specialist complains about incorrect heading hierarchy. Recently we took over a project where a missing <main> and improper alt attributes caused a 30% traffic loss. All this can be avoided by laying down correct semantics, modern CSS, and performance from the start.
We revamped an online store with a CLS of 50% down to a safe level. The original code had numerous absolute positions and lacked semantics. After implementing CSS Grid and Container Queries, metrics improved: LCP dropped from 4.2s to 1.8s, CLS from 0.45 to 0.03. Traffic grew by 15% within two weeks of relaunch. We've seen that quality layout pays off faster than it seems.
Why semantic markup matters — not a religion, but SEO
Browsers and search engines build an accessibility tree from HTML. Errors in semantics cost dearly: incorrect heading structure lowers rankings, missing <main> or <nav> breaks indexing. Using landmark elements like <header>, <footer>, <aside> improves screen reader navigation and gives Lighthouse bonuses. We always follow the recommendations of MDN Web Docs for semantic HTML.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Page Title — Site Name</title>
<meta name="description" content="...">
<link rel="preload" href="/fonts/inter.woff2" as="font" type="font/woff2" crossorigin>
</head>
<body>
<header role="banner">
<nav aria-label="Main navigation" tabindex="0">...</nav>
</header>
<main id="main-content">
<article>
<header><h1>Heading</h1></header>
<section>...</section>
</article>
<aside aria-label="Additional">...</aside>
</main>
<footer>...</footer>
</body>
</html>
Modern CSS: what we use
Our CSS stack solves tasks that used to require JavaScript. Compare: CSS Grid builds complex two-dimensional layouts in a few lines, while Flexbox is good for one-dimensional arrangements. In 9 out of 10 cases Grid is better than repeated float or display:table. Below is a comparison of approaches:
| Feature |
CSS Grid |
Flexbox |
| Direction |
Two-dimensional (rows and columns) |
One-dimensional (row or column) |
| Typical use |
Grids, galleries, dashboards |
Navbars, inline cards, centering |
| Old browser support |
Modern (Edge 16+) |
Modern (Edge 12+) |
CSS Custom Properties — our design system:
:root {
--font-sans: 'Inter', system-ui, sans-serif;
--space-md: 1rem;
--color-accent: hsl(221 83% 53%);
}
How Container Queries change responsiveness
Container Queries allow a component to adapt to its container's width rather than the viewport. This is especially useful for reusable cards: the same card will display correctly in a narrow sidebar and in wide content. Learn more on MDN. This technique reduces the number of media queries by 30% and makes code more predictable. Here's how to implement Container Queries:
- Define the container:
container-type: inline-size;
- Use
@container (min-width: 400px) { ... }
- Nest styles inside the container.
Example of a card layout with Container Queries
.card-container {
container-type: inline-size;
}
@container (min-width: 300px) {
.card {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 1rem;
}
}
How we achieve LCP ≤ 2.5s
We inline critical CSS in the head (about 2–3 KB), and load the rest asynchronously:
<style>/* critical */</style>
<link rel="stylesheet" href="/css/main.css" media="print" onload="this.media='all'">
CSS Containment (contain: layout paint) isolates element repaints. We use will-change only for animated modals. Final metrics we guarantee:
| Metric |
Target value |
| LCP |
≤ 2.5 s |
| CLS |
< 0.1 |
| TBT |
< 200 ms |
We guarantee these values for all projects. The cost is calculated individually based on layout complexity and number of pages. Request a preliminary consultation — get a commercial offer within one day.
How critical CSS reduces load time
Critical CSS is the styles needed to render the first screen. We inline them in the head, and load the rest asynchronously. This reduces FCP and LCP. In one project, we cut FCP from 3.2s to 1.1s just with critical CSS. We also use CSS Containment to isolate repaints. Result: smooth rendering without jumps.
Common layout mistakes
One frequent issue is missing width and height on images — this causes CLS when images load. Solution: set fixed dimensions in HTML or use the aspect-ratio CSS property. Another common mistake is forgetting overflow: hidden on containers with rounded corners (border-radius), causing content to leak. We always check for these.
What's included in our work
- Documentation: style guide for components.
- Deliverables: source files (Figma, code).
- Training: explanation of structure for developers.
- Support: warranty period after delivery.
We are a team with extensive layout experience and 20+ completed projects. We guarantee cross-browser compatibility in Chrome, Firefox, Safari, and Edge. Contact us — we'll evaluate your project within one day.
| Stage |
Duration |
| Landing page (1 screen) |
0.5–1 day |
| Landing page (6–8 sections) |
1–2 days |
| Corporate site (5–10 pages) |
3–5 days |
| Online store (templates) |
5–8 days |
Pricing is individual. Get a consultation to discuss your project details.
Frontend Development with React: From Audit to Production
Bundle grew to 3.1 MB gzip — that's a real figure from a project that came to us for an audit. The cause: moment.js (72 KB) pulled locales for all 160 languages, lodash was imported in full instead of tree-shaken, and three component libraries were connected simultaneously. TTFB was excellent, but TTI on mobile was 14 seconds. Users left, conversion dropped by 40%. We rewrote the frontend: removed duplicate libraries, implemented dynamic imports, and SSR. Result: bundle reduced to 850 KB gzip, TTI to 2.1 seconds, LCP to 1.8 s.
Frontend is not about "drawing prettily". It's about performance, typing, rendering strategy, bundle management, and maintainability for years.
Why is Next.js the Standard Choice for SEO?
React is our primary UI framework for complex interfaces. Next.js is the standard choice for projects with SEO requirements or SSR. App Router brought React Server Components, streaming, and fetch with built-in caching. Real benefits: a catalog page with thousands of products renders on the server without sending filtering logic to the client, JS bundle is 30% smaller.
But App Router is a different way of thinking. "use client" must be placed consciously. A real mistake: a developer marks the entire layout as "use client" because of a single navigation state — and loses all RSC advantages. Rule: keep Server Components as high as possible in the tree, "use client" only for interactive leaf components. ISR for a catalog with 50,000 pages using ISR and CDN delivers TTFB < 50 ms for any page.
How Does TypeScript Prevent Bugs in Production?
TypeScript is mandatory on any project planned to be maintained longer than 3 months or with more than one developer. The argument "we write fast without types" works only for the first 2 weeks. After that, bugs related to undefined values appear every week.
Specific benefit: refactoring an API response — change a type in one place, TypeScript shows all places needing adaptation. Without types, a production bug appears in a week. strict: true in tsconfig.json is mandatory. noImplicitAny, strictNullChecks, strictFunctionTypes. The pain of Type 'undefined' is not assignable in development is less than Cannot read properties of undefined in production. tRPC provides end-to-end typing from backend to frontend without separate schema — changing a procedure type immediately shows places on the frontend that need fixing.
Vue 3 + Nuxt 3 — An Alternative SSR Stack
Vue 3 with Composition API offers a different development style, closer to React Hooks. <script setup> and composables make code more reusable. Nuxt 3 is a framework for Vue with SSR/SSG, similar to Next.js. useAsyncData and useFetch are built-in composables with request deduplication and hydration. Auto-imports are convenient but can confuse during debugging. Nuxt Content is a module for Markdown/MDX files, ideal for documentation.
Hydration mismatch is a specific pain of SSR in Vue and React. Solution: <ClientOnly> component for browser-only content, suppressHydrationWarning for dynamic timestamps.
Performance: Metrics and Tools
Bundle analysis is the starting point. @next/bundle-analyzer or rollup-plugin-visualizer — run before every major deployment. Goal: no page should require > 200 KB JS gzip for first paint.
Dynamic imports for heavy components:
const RichEditor = dynamic(() => import('@/components/RichEditor'), {
ssr: false,
loading: () => <EditorSkeleton />,
});
Editor (Tiptap, Quill, CodeMirror) are typical candidates for dynamic import. Without this, they end up in the main bundle. React DevTools Profiler for finding unnecessary re-renders. React.memo, useMemo, useCallback are targeted tools. Premature memoization of everything adds overhead without benefit. Profile first, optimize later.
Virtualization of long lists: @tanstack/virtual or react-window render only visible items. Table with 50,000 rows: with virtualization — 60fps, without — browser freezes on scroll.
State Management: Without Overengineering
For most applications, it's enough to have:
-
React Query / TanStack Query — for server state (API data, caching, invalidation)
-
Zustand — for global client state (lightweight, no Redux boilerplate)
-
React Hook Form — for forms
Redux Toolkit is justified for very complex global state with many interactions. For most tasks, it's overkill. Recoil, Jotai — atomic approaches for independent pieces of state.
How to Choose the Right CSS and Design System?
Tailwind CSS latest version is our standard choice for new projects. Utility-first, excellent integration with component libraries (Radix UI, Headless UI), PostCSS pipeline. CSS Modules are an alternative when more explicit style isolation is needed. Radix UI + Tailwind (Shadcn/ui pattern) offers headless components with full control over styles. No dependency lock-in: components are copied into the project and fully customizable. Storybook is used for documenting the component library.
React DevTools Profiler — the official tool from the React team.
Testing
| Level |
Tool |
What We Test |
| Unit |
Vitest |
Utilities, hooks, pure functions |
| Component |
Testing Library |
Render, interactions |
| E2E |
Playwright |
Critical user flows |
| Visual |
Chromatic (Storybook) |
UI regression |
E2E tests via Playwright — for checkout, authentication, critical forms. Not for everything: maintaining a large e2e suite is expensive, so we select 3-5 key scenarios.
What's Included in the Scope (Deliverables)
Every frontend project we deliver includes:
-
Source code in Git with full commit history and branching strategy
-
Architecture document — component tree, data flow, routing decisions
-
Component documentation – Storybook with stories for all reusable components
-
CI/CD pipeline – automated builds, linting, tests, deployment config (Vercel / Netlify / custom)
-
Access to staging environment during development and after launch
-
Team training – 2‑3 live walkthrough sessions with your developers
-
3‑month warranty on any bugs found in production
-
Performance report – LCP, TTI, TTFB, bundle size before/after
We also provide a pre‑deployment checklist covering browser testing, security headers, cookie compliance, and accessibility audit.
Estimates and Scope
| Task |
Timeline |
| SPA (dashboard, CRM interface) |
8–16 weeks |
| Next.js site with SSR/ISR |
6–14 weeks |
| Frontend for existing API |
4–10 weeks |
| Component library (design system) |
6–12 weeks |
Cost is calculated after decomposition into components, screens, and API integration. We use N+1 estimation: add 20% for risks.
What Does a Typical Performance Audit Reveal?
A recent e‑commerce project had LCP of 4.2 seconds and a monthly cloud bill of $3,000. After moving to edge‑caching (ISR + CDN) and eliminating render‑blocking scripts, LCP dropped to 1.1 seconds, and the bill fell to $1,800. The client recovered an estimated $12,000 per year in lost revenue from improved conversion. That's the kind of before‑after we regularly deliver.
Comparing tools: Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. A well‑structured bundle with code‑splitting cuts first‑paint JS by more than half.
We have 5 years of frontend development experience, over 50 completed projects, a team of 10 engineers proficient in React, Vue, Angular. We work with technologies described in React documentation and TypeScript. Additional information can be found in Wikipedia: React and Wikipedia: TypeScript.
What Stack to Choose for Frontend Development with React?
We compare tools by real metrics. Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. Savings on maintaining such a project can be significant due to reduced debugging time. If you need a lightweight SPA with minimal cost, React + Vite is enough. For a content site with SEO, Next.js with ISR gives TTFB below 50 ms even with 50,000 pages.
Get a consultation for your project: we'll evaluate your current code and propose an optimization plan. Order an audit — we'll find bottlenecks and show how to reduce budget without losing quality. Contact us to start the discussion.
