David O.

Full-Stack Engineer | Next.js | PostgreSQL | AI SaaS developer

Your Next.js app needs more than someone who knows the framework — it needs an engineer who's shipped production-grade systems, owns the full stack from database schema to deployment pipeline, and won't disappear when things get complicated. That's what I bring. I've spent over 12 years building web and mobile products — the last several years focused heavily on AI integration and model development, Next.js, PostgreSQL, and the modern full-stack ecosystem. I work across the entire lifecycle: architecture decisions, API design, database modelling, CI/CD pipelines on Vercel or any cloud service, and AI feature integration when that's part of the brief. What I typically build: - Next.js apps (App Router, Server Components, SSR/SSG/ISR) - PostgreSQL schemas designed for scale — row-level security, pgvector for AI features, query optimisation - REST and tRPC APIs with TypeScript end-to-end - Auth systems (NextAuth, Clerk, custom JWT flows) - Vercel deployments with CI/CD, preview environments, and environment management - AI-powered features using OpenAI or Claude APIs integrated cleanly into Next.js backends - Python microservices when the job needs heavy data processing or ML alongside the JS stack I've built production systems used by over 5 million users — including official applications across for Telecom giants — and I serve on the United Nations Expert Roster providing AI and engineering consultancy to United Nations (UNDP offices) across the continent. Also Lead Engineer on an AI product in collaboration with Google and Anthropic teams. On Upwork: Top Rated · 100% Job Success Score · If you need a senior engineer who can think through your architecture, write clean code, and ship reliably, let's talk. Next.js · PostgreSQL · TypeScript · Node.js · React · Vercel · Python · REST API · Supabase · CI/CD · Docker · AWS · OpenAI API · Prisma · tRPC · TailwindCSS . Stripe .