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👋 Introduction Hi, I’m a Junior AI & Full-Stack Developer with 6+ years of experience building modern, scalable web applications for startups and growing businesses. I specialize in SaaS platforms, production-ready MVPs, dashboards, and AI-enabled web apps using React, Next.js, TypeScript, and Supabase. My strength lies in combining polished, UX-driven frontend development with a pragmatic, scalable backend, helping founders ship faster without accumulating technical debt. I don’t just write code - I help turn ideas into real, usable products that are ready for users, revenue, and growth. 📌 Current Status ✅ Available for freelance & long-term contracts 🌍 Open to working across all time zones ⏱️ 40+ hours/week if required 🧠 Professional Summary I help startups and product teams design, build, and scale frontend-heavy full-stack applications. My focus is on clean architecture, performance, and maintainability, ensuring the product remains easy to extend as the business grows. Whether you need: - A startup MVP from scratch - A SaaS dashboard with authentication & subscriptions - A Next.js frontend connected to Supabase or APIs - Or AI integrations using OpenAI I can take ownership from concept to production. 🚀 What I Build - SaaS platforms & subscription-based products - Startup MVPs & prototypes (production-ready) - Dashboards & admin panels - AI-powered web applications - Internal tools & data-driven apps 🧩 What I Handle - Frontend architecture & UI systems - Backend APIs, databases & authentication - Payments & subscription billing - Deployment, CI/CD & monitoring - Scaling & long-term maintainability 🛠️ Tech Stack & Skill Set 𝙁𝙧𝙤𝙣𝙩𝙚𝙣𝙙 𝘿𝙚𝙫𝙚𝙡𝙤𝙥𝙢𝙚𝙣𝙩 - React.js - Next.js (App Router, Server Actions, SSR, SSG) - TypeScript & JavaScript (ES6+) - Tailwind CSS, shadcn/ui, Material UI (MUI) - Responsive & UX-focused UI development - State management (Redux Toolkit, Zustand) - Forms & validation (React Hook Form, Zod) - Data visualization (Chart.js, Recharts, D3.js) 𝑩𝒂𝒄𝒌𝒆𝒏𝒅 & 𝑭𝒖𝒍𝒍-𝑺𝒕𝒂𝒄𝒌 - Node.js, Python - Express.js & NestJS - Supabase (PostgreSQL, Auth, RLS, Realtime) - Firebase - REST & GraphQL APIs - Authentication & role-based access - Database design & optimization (PostgreSQL, MySQL, MongoDB) 𝑪𝑴𝑺 & 𝑬-𝑪𝒐𝒎𝒎𝒆𝒓𝒄𝒆 𝑫𝒆𝒗𝒆𝒍𝒐𝒑𝒎𝒆𝒏𝒕 - WordPress Developer, WooCommerce - Shopify Developer, Shopify Admin API - PHP, Laravel - Custom E-commerce Solutions 𝑵𝒐-𝑪𝒐𝒅𝒆 / 𝑳𝒐𝒘-𝑪𝒐𝒅𝒆 𝑫𝒆𝒗𝒆𝒍𝒐𝒑𝒎𝒆𝒏𝒕 - Bubble Developer - Adalo, Glide, Thunkable - AppSheet, Softr, Bravo Studio, AppMySite 𝑪𝒍𝒐𝒖𝒅 & 𝑫𝒆𝒗𝑶𝒑𝒔 - AWS, Docker, NGINX - CI/CD (GitHub Actions, GitLab CI) - Firebase, Supabase, Vercel, DigitalOcean - Linux Server Administration - Database Scaling & Performance Optimization 𝑨𝑰 & 𝑨𝒖𝒕𝒐𝒎𝒂𝒕𝒊𝒐𝒏 - AI Integration, LLMs - OpenAI API, Claude - AI Agents, RAG Pipelines - AI Automation Workflows - Document Processing & Voice AI 𝑷𝒂𝒚𝒎𝒆𝒏𝒕𝒔 & 𝑻𝒉𝒊𝒓𝒅-𝑷𝒂𝒓𝒕𝒚 𝑰𝒏𝒕𝒆𝒈𝒓𝒂𝒕𝒊𝒐𝒏𝒔 - Stripe Integration, Paystack, Flutterwave - Twilio, LiveKit, VoIP Systems - Mapbox Integration - LinkedIn Ads API 𝑺𝒂𝒂𝑺 & 𝑰𝒏𝒕𝒆𝒈𝒓𝒂𝒕𝒊𝒐𝒏𝒔 - Stripe (payments, subscriptions, billing) - OpenAI / LLM API integrations - Third-party API integrations - Webhooks & background jobs 𝑫𝒆𝒗𝑶𝒑𝒔 & 𝑻𝒐𝒐𝒍𝒊𝒏𝒈 - Vercel, AWS - Docker - CI/CD (GitHub Actions) - Monitoring & error tracking (Sentry, PostHog) - Git (GitHub, GitLab) 𝑷𝒓𝒐𝒅𝒖𝒄𝒕𝒊𝒗𝒊𝒕𝒚 & 𝑨𝑰 𝑻𝒐𝒐𝒍𝒔 - Cursor - GitHub Copilot - Claude Code - Replit / Lovable - Prompt Engineering & AI-assisted development 🧪 Experience Highlights - Built and shipped multiple SaaS platforms used by real customers - Delivered startup MVPs from idea to production in weeks - Designed secure Supabase backends with RLS and scalable schemas - Implemented subscription billing systems with Stripe - Created high-performance dashboards and admin panels - Integrated AI features to automate workflows and user interactions 🏷️ Tags / Keywords (SEO Optimized) Senior Full-Stack Developer, Frontend-Focused Full-Stack, SaaS Developer, MVP Developer, Startup Developer, Product Engineer, React Developer, Next.js Developer, TypeScript Developer, Supabase Developer, PostgreSQL, Stripe Integration, Dashboard Developer, Admin Panel Developer, AI Web Developer, OpenAI Integration, Subscription Billing, Scalable Web Apps 🤝 Why Work With Me? - Product-focused mindset (not just tasks) - Clean, maintainable, scalable code - Strong communication & ownership - Startup experience - I understand speed and quality - Long-term thinking, even for MVPs ✅ Closing Statement If you’re looking for a reliable senior developer who can take your idea seriously and turn it into a professional-grade product, I’d be happy to help. Let’s build something impactful 🚀

Hey! I'm Manu. I mainly do front-end and full-stack development. I'm super flexible and can adapt to many industries and use-cases. From authentication, API integrations and/or development, design, server-side rendering, etc. I love to engage with the non-technical side of projects and understand how the business works. This usually leads to better communication and results. I enjoy being proactive and suggesting technical improvements, as what technology/library to choose, UI/UX improvements, or just any valuable contribution I can make. Tech Stack: - SvelteKit, Next js 14, React, Typescript, Tailwind CSS, Node.js - Supabase, Firebase - Firebase, Next Auth, Lucia - UI Development: Shadcn UI, pixel-perfect Figma to Code - PostgreSQL, MySQL, Firestore, SQLite - Prisma, Drizzle ORM, Zod I also really enjoy AI projects. I've worked with: - OpenAI API, GPT-4, Vector Databases, other LLMs - Python, FastAPI, Flask Sounds like a fit? Let's have a call!

I build production AI systems end-to-end — LLM agents, RAG, multimodal pipelines — plus the backend and frontend around them. $300K+ earned across 61 projects and 4,446 hours here on Upwork, for clients in the US, Canada and the EU. Before freelancing I co-founded App in the Air — a travel assistant that reached 7M users and won Apple's App of the Year. 15 years building products; the last two focused entirely on AI. If you need an AI feature — or a whole AI product — shipped by one senior engineer instead of a team, that's my lane. --- What I build --- • Agentic systems — LLM agents with tool-calling / OODA loops across web, Telegram and email: intent classification, field extraction, automated workflows and ticketing. • RAG & context engineering — PostgreSQL/pgvector, hybrid retrieval, context assembly, long-lived memory. • Multimodal pipelines — vision + speech (Whisper), structured outputs on OpenAI / Anthropic / Gemini, schema-validated end to end. • Evals & reliability — self-improving eval loops, regression gating in CI, per-tier cost guards, provider fallback chains, full observability (Langfuse). • The product around the model — Node/TypeScript backends, Temporal durable workflows, React/Vue frontends, Docker, CI/CD. The AI layer is useless without the system that carries it; I build both. --- Recent work --- • Agentic support system for a B2B GPU-infrastructure company (contract, under NDA) — end-to-end LLM-agent support across Telegram / Email / Web: OODA tool-calling loop, multimodal intake (vision + Whisper STT), self-improving eval loop over 45+ real cases, ~120K LOC. • B2B brand-creator marketing platform (contract, under NDA) — Temporal workflow engine and an AI provider control plane (cost ledger, rate limiting, circuit breakers), plus a skills-based LLM generation system (18+ domain skills) with guardrails and quality evals. • Noracle — a live, monetized AI SaaS I built and shipped solo: 5-stage LLM pipeline with provider fallback and per-tier cost guards, Telegram Stars billing, 38% D30 retention among paying users. • Viracle — AI video-virality analytics: event-driven backend (Fastify, Temporal, 4 microservices), multimodal video analysis on Gemini structured outputs, and a 7-stage Python ML pipeline (correlation, clustering, anomaly detection to content directives). • Independent AI research (2025-26) — interpretability and efficient architectures: extracting exact, verifiable logic from trained networks. I understand models below the API line, which is what makes the engineering hold up in production. --- Best fit --- You have an AI feature or product to ship and no appetite for hiring a team. You want one person who can own the whole thing — model layer, backend, frontend, infra — and tell you straight what will and won't work. Consultation, MVP / PoC, or a long-term build. --- Stack --- AI / LLM: OpenAI, Anthropic, Gemini, Vercel AI SDK, agentic tool-calling, RAG / pgvector, Whisper STT, vision, structured outputs, Langfuse, LLM evals Backend: Node.js, TypeScript, Fastify / Express, Temporal, Redis / BullMQ, PostgreSQL (Drizzle, pgvector), MongoDB Frontend: React, Vue / Nuxt, TypeScript, Tailwind, design systems Data / ML: Python, PyTorch, scikit-learn, Pandas, data & scraping pipelines Infra: Docker, CI/CD, Prometheus / Grafana / Jaeger / OpenTelemetry, GCP / AWS Based in Buenos Aires (UTC-3) — full overlap with US business hours.

I am passionate about problem-solving and thrive in a team-oriented environment. I have a quick learning ability, and I enjoy exploring new technologies while continuously improving my proficiency in those I already use.

Hi, I’m Juan, a Frontend Developer specialized in building fast, scalable, and interaction-heavy web applications with React and TypeScript. I don’t just “turn designs into code”. I help clients ship reliable frontends that perform well, scale cleanly, and are easy to evolve, even when the UI logic gets complex. What I do best Advanced React development (hooks, context, state architecture) TypeScript-first mindset for maintainable and predictable code High-performance UIs (memoization, virtualization, render control) Complex frontend logic (dashboards, flows, graphs, dynamic layouts) Pixel-perfect implementations from Figma Modern styling with Tailwind / component systems Clean integration with APIs (REST, auth flows, async state) AI-assisted development (Cursor / Claude) with senior-level review and refactoring Tech stack React 18/19, Vite, TypeScript Zustand / Redux / TanStack tools Tailwind CSS, component libraries React Flow & custom canvas-style UIs Git, GitHub, collaborative workflows How I work I focus on: Clear architecture from day one Readable, production-ready code (not “AI spaghetti”) Performance and UX, not just visuals Direct, honest communication

Hi there! 👋 I'm a highly skilled Full Stack web developer with 3 years of experience in modern technologies like ReactJs, NextJs, MongoDB, Express, Node and CSS libraries such as Tailwind, MUI, and Shadcn. • I believe effective communication and exceeding expectations are pivotal aspects of any successful collaboration. • Your vision and input regarding the project hold immense value to me, as my aim is to deliver a high-quality web application that aligns perfectly with your requirements. • I have experience working with startups, small and medium-sized enterprises, as well as large companies. My expertise encompasses a range of technologies, including: 📌 React, Redux , NextJS 📌 Typescript, JavaScript 📌 HTML, CSS 📌 TailwindCss, Material UI, Shadcn 📌 NodeJS, Express, MongoDB, PostgreSQL 📌 Figma 📌 Git, Github, Bitbucket, Gitlab By harnessing these tools, I can develop innovative solutions tailored to your unique needs. Feel free to explore my portfolio for a deeper understanding of my capabilities and the projects I've worked on. If you're seeking a dedicated and proficient Full Stack web developer to bring your ideas to life, I am confident that I can be of great assistance. Let's collaborate and create something great together! Shoot me a message if you'd like to work together on your next or ongoing project!