Svelte and SvelteKit code review, security, and deployment services
Svelte and SvelteKit are gaining traction as a modern alternative to React, and tools like Bolt and Cursor can generate Svelte projects. Svelte's compiler approach produces smaller bundles, but vibe coded Svelte apps often have issues with store management, SvelteKit routing, and server-side security that require expert review.
Common Svelte issues we find
Real problems from Svelte codebases we've reviewed.
Unprotected SvelteKit server routes
SvelteKit +server.ts endpoints without authentication checks. Since these look like regular files in the routes folder, AI tools often forget they're publicly accessible API endpoints.
Sensitive data in load functions
Server load functions returning sensitive data that gets serialized to the client. Everything returned from +page.server.ts load is visible in the page's HTML source.
Store subscriptions causing memory leaks
Manual store subscriptions ($: syntax works in components, but manual subscribe() calls in modules need explicit unsubscribe to avoid memory leaks).
Missing form validation
SvelteKit form actions that process submitted data without validating fields, types, or sizes — trusting whatever the user sends.
Incorrect use of derived state
AI-generated Svelte code uses reactive statements ($:) for complex derived data without memoization, recalculating expensive operations on every state change.
No error page at route level
Missing +error.svelte pages, so when something goes wrong, users see SvelteKit's default error page instead of your brand's error experience.
Client-side environment variable exposure
Secrets placed in PUBLIC_ prefixed env vars (which are sent to the browser) instead of private env vars that stay on the server.
Missing adapter configuration
SvelteKit projects using the default adapter-auto that may not match the deployment target, causing build failures or missing features in production.
Svelte production checklist
Key checks before deploying your Svelte app.
All +server.ts endpoints verify authentication
Server load functions don't return sensitive data to client
Store subscriptions properly cleaned up
Form actions validate all input data
Error pages (+error.svelte) at root and key route groups
Secrets in private env vars (not PUBLIC_ prefixed)
Correct SvelteKit adapter for deployment target
Prerendering enabled for static pages
CSP headers configured in hooks.server.ts
Loading states for data fetching in +page.ts
Not sure if your app passes? Our code audit ($19) checks all of these and more.
Our Svelte services
Security Review
Deep security analysis of your application — from API endpoints to database access.
Deploy & Ship
From local development to production deployment.
Refactor Code
Clean up messy, duplicated, and hard-to-maintain code without breaking what already works.
Performance
Identify and fix performance bottlenecks — slow page loads, laggy interactions, and expensive operations.
AI tools that generate Svelte code
Start with a self-serve audit
Get a professional review of your Svelte project at a fixed price.
Security Scan
Black-box review of your public-facing app. No code access needed.
- OWASP Top 10 checks
- SSL/TLS analysis
- Security headers
- Expert review within 24h
Code Audit
In-depth review of your source code for security, quality, and best practices.
- Security vulnerabilities
- Code quality review
- Dependency audit
- AI pattern analysis
Complete Bundle
Both scans in one package with cross-referenced findings.
- Everything in both products
- Cross-referenced findings
- Unified action plan
100% credited toward any paid service. Start with an audit, then let us fix what we find.
How it works
Tell us about your app
Share your project details and what you need help with.
Get a clear plan
We respond in 24 hours with scope, timeline, and cost.
Launch with confidence
We fix what needs fixing and stick around to help.
Frequently asked questions
Can you review a SvelteKit app built with an AI tool?
Yes. We review SvelteKit applications for server route security, data exposure in load functions, store management issues, and deployment configuration. Svelte has unique patterns that need specific expertise.
Is SvelteKit ready for production?
Absolutely. SvelteKit is stable and used by major companies. The issue is not the framework — it's how AI tools generate the code. We make sure your SvelteKit app is properly secured and optimized.
How does Svelte compare to React for performance?
Svelte compiles to vanilla JavaScript with no runtime framework overhead, so bundles are smaller and initial load is faster. We help you take full advantage of Svelte's performance characteristics.
Related resources
Need help with your Svelte project?
Tell us about your project. We'll respond within 24 hours with a clear plan and fixed quote.