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Anton C.
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Anton C.

React Developer Full Stack Developer SaaS Front End Developer Next.js

👋 Hi! My name is Anton. I'm a React Developer, AI Developer specializing in SaaS, AI-powered web applications, and B2B platforms. I have 6+ years of experience delivering 300+ projects for SaaS, AI, and B2B clients. My work also spans Full Stack Developer React Node and Front End Developer work — production-ready code, built for founders shipping SaaS, AI, and B2B products, with a React Developer who owns the whole process. ⭐ Top Rated Plus React Developer 📅 6+ years as a React Developer 📦 300+ projects delivered ⏱️ 5,000+ Upwork hours as a React Developer 🔁 ~70% returning clients ✅ Why hire me as a React Developer ▪ As a React Developer and Full Stack Developer, I bring 10+ years of experience across SaaS, AI, and B2B platforms. ▪ As a React Developer, I've delivered 70+ projects, plus 300+ broader engagements as a Full Stack Developer React Node. ▪ As a React Developer, I've logged 5,000+ Upwork hours across React Native Developer and Full Stack Developer React Node work. ▪ Top Rated Plus status reflects steady, on-time delivery as a Front End Developer. ▪ A React Developer at the core, shipping production-ready code with React, Next.js, and TypeScript — spanning Full Stack Developer React Node and Web Developer work. ▪ As a Full Stack Developer React Node, I ship SaaS MVPs ~30% faster to market, with ~25% fewer post-launch bugs. ▪ As a Front End Developer, I maintain production platforms at 99%+ uptime, with zero-downtime deployments on 90%+ of releases. ▪ As a React Developer, I optimize front-ends that load up to 40% faster and scale to 10,000+ active users. ▪ Using AI-assisted workflows as a Full Stack Developer React Node, I cut development costs by ~20% and speed delivery by ~30%. 🏗️ Full-Stack SaaS & B2B Platforms As a React Developer and Full Stack Developer React Node, I build multi-tenant B2B SaaS platforms with React, Next.js, and Node.js — authentication, role-based access control, and full Stripe billing (Subscriptions and Connect), backed by PostgreSQL via Prisma with REST and GraphQL APIs on AWS. On the AI side, as a Full Stack Developer AI, I build AI-powered SaaS products with the OpenAI and Anthropic APIs — RAG pipelines, embeddings, semantic search, Supabase Realtime, and PWAs on Vercel. 🖥️ Front-End & React Development As a Front End Developer React specialist, I deliver Front-End Development with Core Web Vitals-optimized, accessible interfaces with App Router, Server Components, SSR/SSG, and ISR. Firebase-backed projects get the same coverage as a React Developer Firebase build. Next.js builds run through me as a React Next JS Developer and Front End Developer Next.js, and AI interfaces as a Front End Developer AI. My work also covers marketplaces, e-commerce, booking systems, real-time chat, and analytics dashboards, extending to iOS and Android as a Mobile App Developer and React Native App Developer with React Native and Expo. 🧭 Process Every engagement as a React Developer opens with scoping the business problem, then architecture, build, testing, and CI/CD — the same process behind every Full Stack Developer React Node platform and Front End Developer build. ⚙️ Tech Stack As a React Developer, I build the frontend with React, Next.js, TypeScript, HTML5, CSS 3, and JavaScript, styling with Tailwind CSS or Bootstrap and handling state with Redux or Zustand. The backend runs on Node.js via Express or NestJS with PostgreSQL, OpenAI, Claude, Codex, Prisma, Supabase, or Firebase, deployed to AWS or Vercel via GitHub Actions. 🧩 Mixed-Stack Support Python, PHP, Laravel, MySQL, MongoDB, WordPress, jQuery, and Vue.js round out the toolkit. As a Python Developer or Python Full Stack Developer, I take on Python-backed services. As a WordPress Developer, Shopify Front End Developer, or Full Stack Developer Shopify, I handle inherited-code work on request, with Web Design and Responsive Design principles carrying through. 🏭 Industries SaaS & B2B, AI Startups, Marketplaces & E-commerce, Fintech, Healthtech, Ed-tech, AI Platform, AI Integration, and Real estate — where my React Developer and Full Stack Developer work has landed. 🎯 What clients hire me for Scalable web applications, secure REST and GraphQL APIs, high-performance Next.js front-ends, and reliable, production-ready SaaS — that's what clients bring a React Developer on for. Full Stack Developer React Node and Front End Developer let me deliver end to end, backed by 300+ engagements, ~30% faster time-to-market, and 99%+ uptime. About 70% of my clients return for repeat engagements as a React Developer. Building, scaling, or improving a product? I work as a React Developer, backed by Full Stack Developer React Node, Front End Developer, React Native Developer, and Web Developer — let's talk. 👇

🇪🇸Barcelona, Spain$35/hr100% JSS4.86 (61)Since Nov 2015
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Earnings and projects

MRR
$3.5k

Last 6 months ÷ 6

World#10,214 / 412k
🇪🇸Country#129 / 4,023
Revenue, last 30 days
$750

Last 6 months: $21k

World#51,705 / 412k
🇪🇸Country#431 / 4,023
Total earnings
$464k

Billed in all: $480k

World#3,267 / 412k
🇪🇸Country#55 / 4,023
Per project
$5.9k

$2.6k in the last 6 months

World#29,459 / 412k
🇪🇸Country#298 / 4,023
Projects, last 6 months
8
63% fixed37% hourly
World#24,501 / 412k
🇪🇸Country#196 / 4,023
Projects in all
79

Across 81 contracts

38% fixed62% hourly
World#37,268 / 412k
🇪🇸Country#362 / 4,023

Earnings, last 30 days

$480k+$750 earned in the last 30 daysBilled in all, before Upwork's fee · drag across the chart to see what was earned in any stretch
$479.0k$479.5k$480.0k$480.5kOct 9Oct 24Nov 8

Skill rankings: Top 2% in Bootstrap

Ranked by MRR among everyone on Upwork with the skill.

  1. #113Redux3,245 freelancers · 🇪🇸 #3Top 3%
  2. #146Bootstrap6,899 freelancers · 🇪🇸 #5Top 2%
  3. #245CSS 39,914 freelancers · 🇪🇸 #4Top 2%
  4. #271Responsive Design9,915 freelancers · 🇪🇸 #6Top 3%
  5. #326Front-End Development8,892 freelancers · 🇪🇸 #7Top 4%
  6. #364Vue.js8,268 freelancers · 🇪🇸 #5Top 4%
  7. #378HTML514,581 freelancers · 🇪🇸 #7Top 3%
  8. #402MongoDB10,865 freelancers · 🇪🇸 #6Top 4%