Svelte development company
SvelteKit applications, Svelte 5 migrations, and compiled widgets that stay small in the browser. Our engineers plan load functions, form actions, and adapters around your hosting, so pages render on the server and keep working before JavaScript arrives.
- 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
Svelte and SvelteKit built for production
Krapton is a Svelte development company that builds SvelteKit applications, moves Svelte 4 codebases to Svelte 5 runes, and ships embeddable components for teams that watch how much JavaScript reaches the browser. Svelte compiles components into direct DOM updates instead of shipping a virtual DOM, which suits content-heavy sites, dashboards, and widgets that load inside other people’s pages. It is a weaker fit when you need React Native code sharing, a React-only design system, or the deepest possible hiring pool, and discovery is where we say so. On SvelteKit projects, each route gets a rendering decision early: prerendered, server-rendered, or client-only. Secrets stay in $env/static/private, per-request data lives in event.locals rather than module-level stores, and forms use actions that work before hydration. From the first commit, svelte-check, Vitest, and Playwright run in CI, which keeps the codebase maintainable after handover.
Svelte development services
SvelteKit application builds
Full-stack SvelteKit apps with typed load functions, form actions, hooks for auth and logging, and the adapter that fits your platform: Node, Vercel, Netlify, Cloudflare, or a static export.
Svelte 5 runes migration
Svelte 4 components moved to $state, $derived, $props, and snippets, starting with the sv migrate tool and then hand-fixing the event dispatchers, slots, and reactive statements it leaves behind.
Embeddable web components
Components compiled as custom elements, so a booking form, product configurator, or chat panel drops into WordPress, Shopify, or a legacy app without the host page adopting a framework.
SSR and performance tuning
Fixes for load-function waterfalls, oversized client bundles, and hydration mismatches, plus per-route prerendering, streamed promises for slow data, and cache headers that suit your CDN.
Forms, auth, and data
Progressively enhanced forms with Superforms and Zod, sessions handled in hooks.server.ts through Auth.js or Better Auth, and database access via Drizzle or Prisma kept on the server.
Rescue and maintenance
Takeover of an inherited Svelte or Sapper codebase: documentation first, tests around the riskiest routes next, then steady upgrades to SvelteKit, Vite, and adapters as new majors land.
Why teams choose Krapton for Svelte
Senior engineers, fixed scope, and code you own — the things agencies promise and rarely deliver.
Honest framework fit advice
Svelte is not the answer for every product. If your roadmap needs React Native, a React-only component suite, or a very large local hiring market, you hear that before any code is written.
Server boundaries kept explicit
Private data loads in +page.server.ts and +layout.server.ts, never in universal load files, so API keys and internal URLs cannot end up in the client bundle.
Reactivity without effect sprawl
Reviews check that computed values use $derived and that $effect is reserved for real side effects, because effects used to sync state are a frequent cause of update loops.
Tests that match the framework
Component tests run in Vitest with Testing Library, end-to-end flows run in Playwright against a production build, and svelte-check fails the pipeline on type errors in markup.
How a Svelte project runs with Krapton
01
Route-level discovery
We map each page to a rendering mode, list the data each load function needs, and flag libraries that assume React or touch window during server rendering.
02
Components and state
Shared state moves into .svelte.ts modules using runes, primitives and design tokens come first, and compiler accessibility warnings are treated as defects, not noise.
03
Preview-based delivery
Every pull request gets a preview deployment, so you click through a real SvelteKit build, comment in context, and approve behavior before anything merges.
04
Launch and handover
Adapter settings, cache headers, and error pages are verified in production, then you receive runbooks, environment variable docs, and a dependency upgrade plan.
The Svelte stack we build with
Svelte development: questions answered
Which projects suit a Svelte development company best?
Interactive web products where page weight and responsiveness matter: SaaS dashboards, content sites with app-like sections, booking and checkout flows, internal tools, and widgets embedded in other sites. A Svelte development company can also migrate Svelte 4 or Sapper code, fix SSR performance, and build design systems. At Krapton the same engineers own routing, server load functions, forms, tests, and deployment adapters, so nothing falls between separate frontend and backend vendors.
When is Svelte the wrong choice?
When the product depends on React-specific tooling or hiring scale. Sharing code with a React Native app, adopting a design system that only ships React components, or staffing a large in-house team quickly in a React-dominated market all point away from Svelte. A mostly static site may not need it either, since Astro or plain HTML would do. For interactive apps with tight performance budgets, Svelte is usually a strong fit.
How do you migrate a Svelte 4 app to Svelte 5?
Incrementally, because Svelte 5 still runs Svelte 4 syntax in legacy mode, one component at a time. We upgrade the packages, run the sv migrate tool, and fix what it leaves: event dispatchers, slot-based APIs that become snippets, and $: statements that should be $derived rather than $effect. Each converted batch gets tests before the next one starts, so feature work continues during the migration.
Can SvelteKit handle heavy traffic and complex data?
Yes, if rendering and caching are planned per route. Prerender pages that rarely change, server-render personalized ones with sensible cache headers, and stream slow data rather than blocking the page. Keep queries in server load functions, run independent requests in parallel to avoid waterfalls, and put a CDN in front of the adapter output. In SvelteKit apps, scaling problems usually trace back to data access rather than the framework.
What decides the cost of a Svelte project?
The number of routes, user roles, and integrations sets most of the effort. Other drivers are data coming from third-party APIs, any Svelte 4 or React code that must be migrated, authentication and compliance requirements, and how much automated test coverage you want at launch. Those items are written into the scope after discovery, so the estimate maps to features you can check one by one.
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.