Anton K.
Senior Full-Stack Engineer | AI SaaS | Next.js, React, Supabase
I’m a full stack developer, react developer, and web developer helping businesses build, fix, and improve SaaS products, web applications, dashboards, internal tools, and client platforms with react, next.js, node.js, supabase, postgresql, API integration, and AI-powered workflows. As a full stack developer, I work across front end and back end development. As a react developer and next.js developer, I build and improve modern web application interfaces, dashboards, admin panels, and client-facing product flows. As a node.js developer, I work on business logic, API integration, authentication, webhooks, oauth, stripe flows, and product functionality that supports real SaaS and web application use cases. My work often combines react, next.js, node.js, javascript, typescript, supabase, and postgresql inside one product. Clients usually hire me when they need a full stack developer who can do more than isolated tasks. They need a react developer who can work inside a real product, a next.js developer who can improve an existing web application, and a node.js developer who can connect front end and back end logic cleanly. I help build MVPs, improve SaaS products, fix broken web applications, stabilize dashboards, extend internal tools, improve client portals, and support existing codebases that need stronger full stack development. A lot of my work is with react, next.js, and node.js products that already exist but need improvement. That can mean bug fixing, maintenance, stabilization, performance improvement, API integration, dashboard development, admin panel development, auth flow fixes, web application cleanup, SaaS feature delivery, or extending an MVP into a more production-ready SaaS platform. I’m comfortable joining an existing codebase and working as a full stack developer, react developer, next.js developer, or node.js developer depending on what the product needs most. I also work with supabase and postgresql when a SaaS product or web application needs database logic, authentication, real-time functionality, role-based access, or cleaner back end structure. In many projects, react, next.js, node.js, supabase, and postgresql work together as the core stack, and that is a stack I’m comfortable building, fixing, and extending. I regularly work on web application and SaaS development that includes API integration, stripe, oauth, webhooks, dashboards, internal tools, and client-facing product flows. As a react developer, I can help build responsive product UI, dashboard UI, admin interfaces, and front end functionality inside larger web applications. As a next.js developer, I can help with product architecture, page flows, performance, routing, feature delivery, and production-ready SaaS implementation. As a node.js developer, I can help with API integration, back end logic, business workflows, third-party services, and server-side product functionality. As a full stack developer, I can connect all of those layers into one working product. I also work with AI when it supports a real SaaS or web application use case. That includes AI integration with OpenAI or Claude APIs, AI-assisted product features, AI workflows inside dashboards and internal tools, and automation that supports web application, SaaS, or client platform functionality. When useful, I can also support web scraping and automation if it fits the product and strengthens a real business workflow. If you need a full stack developer, react developer, next.js developer, node.js developer, or web developer for a SaaS product, web application, dashboard, internal tool, API integration project, MVP, client portal, supabase app, postgresql-based system, or AI-powered product feature, send me a message and I’ll review your project.
Earnings and projects
An estimate from an earlier read
Last 6 months: $34k
Billed in all: $151,831$152k
$5.7k in the last 6 months
Across 7 contracts
Across 46 contracts
Earnings, last 30 days
No data since Nov 5, 2026.
Skill rankings: Top 1% in HTML5
Ranked by MRR among everyone on Upwork with the skill.
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