Juan U.

Next.js + AI Developer | Premium SaaS Apps & LLM Integrations

I build production-ready NextJS apps and AI integrations (OpenAI, Claude, LangChain, vector search, RAG) for startups that need to ship fast without shipping trash. Top Rated Plus · 100% Job Success · 1,800+ hours delivered. Recent work: • Pulse — fitness SaaS I co-founded and built. React Native + Node + Postgres, architected to scale from 100 to 10K+ users. • Spawned — AI-powered app builder with real-time build streaming (Socket IO, Redis, BullMQ, Solana). • White Rock Millwork, Sembroni, BFL — premium marketing sites built in NextJS 15 with GSAP and Framer Motion. Where I fit best: → Early-stage founders who know what they want and want it shipped → Agencies that need NextJS and React overflow capacity → Established teams adding AI (OpenAI, Claude, LangChain) to an existing product Real numbers from past roles (not LinkedIn fluff): • Reduced error resolution time by 53% on an enterprise AI chatbot (text, voice, image) • Increased Stripe payment success rate by 40% via checkout refactor • Cut deployment time from 30 min to under 5 min with GitHub Actions + DigitalOcean CI/CD • Built a Python microservice (FastAPI, NumPy, Pandas) analyzing millions of poker hands in under 50ms Tech I use daily: NextJS (App Router), TypeScript, React, React Native, Tailwind, Framer Motion, GSAP · NodeJS, Express, Python (FastAPI), PostgreSQL, MongoDB, Prisma, Redis, BullMQ · OpenAI API, Claude API, LangChain, AI agents, vector search · Stripe, GoHighLevel, Meta Pixel CAPI, Socket IO · AWS, Docker, Terraform, GitHub Actions, Vercel, DigitalOcean What clients have said: "Juan did an excellent job on this task, despite it being in a new area where he had limited prior experience. He quickly got up to speed, demonstrating a remarkable ability to learn and adapt... I was consistently impressed by his strong communication skills and his proactive approach." — Angela Wu, Founder at Komo AI "Juan is excellent! Very responsive and on-time on deliverables." — Domenica Cheek, CEO at Avanti Creativo I'm fluent in English and Spanish and respond to messages in under 4 hours. If you send a clear brief, I'll come back with a scoped estimate and — if the job warrants it — a short Loom walking through how I'd build it.