Henry N.

Senior Full-Stack Engineer specializing in high-performance Next.js architectures, scalable APIs, and secure data workflows. Maintained a single enterprise client (Savisoft) continuously for 31 months with 2,400+ hours billed and 100% JSS Core Engineering: Next.js App Router, TypeScript, React Server Components, NestJS, Supabase/PostgreSQL. Security & Compliance (HealthTech ready): Zero-PHI retention architecture, AWS CDK infrastructure, Zod runtime schema validation (chống AI hallucination), HIPAA-aware data flows. I fix and ship apps built with Claude Code, Cursor, Lovable or Replit that work in the demo but break in production: auth, Supabase RLS, payments, deploys. 10+ years senior full-stack, 100% JSS, 3,150+ hours. For new products: production-ready MVPs in Next.js + Supabase. For existing products: I take over Python/Node codebases and ship without breaking production. BACKGROUND & TRACK RECORD: • 10+ years of professional software engineering: 6+ years in product tech companies building enterprise software, followed by 5+ years building and scaling production systems for US & European clients on Upwork. • Top Rated, 100% Job Success Score, 3,150+ hours logged, $70K+ earned. • Proven long-term client retention: 31 consecutive months partnering with Savisoft UG (Savicase CRM/DMS & Cloud, 2,100+ hours, 5.0 stars). CORE TECHNICAL STACK: • Frontend: Next.js (App Router, Server Actions, SSR), React, TypeScript, Tailwind CSS, TanStack Query • Backend & APIs: Python (Django, FastAPI), Node.js / Express, RESTful & GraphQL APIs • Databases & Architecture: PostgreSQL, Supabase, pgvector, Prisma, MongoDB, multi-tenant isolation, RLS • AI & Automation: RAG pipelines, OpenAI / Anthropic APIs, vector search, workflow automation • DevOps & Cloud: Docker, AWS, Vercel, CI/CD pipelines, Sentry, monitoring HOW I WORK: • High ownership & async communication: Clear daily/weekly updates, clean PRs, zero hand-holding needed. • AI-native speed + Senior engineering rigor: Rapid implementation powered by modern AI tooling paired with strict architectural standards, testing, and clean code principles. • Flexible collaboration: Available 15–25 hrs/week per client for ongoing, long-term partnerships If you need an experienced senior engineer who treats your product with true ownership, feel free to send an invitation or schedule a brief introductory call.