Serhii S.

I build AI-powered SaaS platforms and full stack web applications from MVP to production using React, Next.js, Node.js, TypeScript, and Supabase. I help startups and businesses turn ideas into scalable, production-ready products - not just prototypes or demo apps. What I specialize in: - Multi-tenant SaaS platforms with authentication and billing - AI-powered applications and workflow automation - Dashboards, admin panels, and internal tools - API-driven web applications and client portals How I work: - I can join an existing codebase or build a system from scratch. My focus is clean architecture, scalability, and shipping production-ready features. - I work across both frontend and backend to ensure the system is stable, maintainable, and properly connected. Typical tasks I handle: - Building and launching MVPs for SaaS products - Improving existing applications - Fixing backend, API, and authentication issues - Integrating services (Stripe, OAuth, webhooks) - Optimizing performance and scalability Tech stack: - Front-end: React.js (Next.js, Vite), Redux, Zustand, React Query, TailwindCSS, Material UI. - Back-end: Node.js, Express.js, Nest.js, Supabase, REST APIs - Databases: PostgreSQL, MySQL, MongoDB, Firebase - CI/CD and DevOps: GitHub Actions, Docker, Kubernetes, Azure Pipelines - Email and notifications: Resend, SendGrid, Mailgun, AWS - Authentication and security: OAuth 2.0, JWT, Firebase Auth, Auth0 AI & automation: - I integrate AI features into SaaS products where it adds real value - including OpenAI-based features, automation workflows, and intelligent backend systems. If you're building a SaaS product, AI application, dashboard, or web platform and need a full-stack engineer who can take it from idea to production - feel free to reach out. I also help founders improve, refactor, and scale applications initially built with AI development tools such as Cursor, Lovable, Bolt.new, Claude, and v0, turning early MVPs into maintainable production-ready products.