j
john_frantzis

John F.

@john_frantzis
Grécia
Inglês
Algumas informações são exibidas no idioma inglês.
Sobre mim
Full-stack SaaS & AI engineer building production systems end-to-end. I design scalable architectures, implement multi-tenant backends, and ship revenue-driven automation using TypeScript, Node.js, React and PostgreSQL. Specialized in: • AI agents for voice, email and workflow automation • Stripe billing & subscription lifecycle • Secure integrations (REST APIs, webhooks, async jobs) • Real-time dashboards & analytics • Supabase with RLS and Edge Functions I turn complex product ideas into fast, stable and monetizable platforms.... Saiba mais

Habilidades

j
john_frantzis
John F.
offline • 

Conheça meus serviços

Aplicações Web Full Stack
I will build your saas mvp from idea to production
A partir deUS$ 500 /projetoMais detalhes
Automações e Agentes
I will build ai agents for automation and ai phone call systems
A partir deUS$ 300 /projetoMais detalhes

Portfólio

Experiência profissional

Invoice-Lens.com

Invoice lens • Autônomo

Aug 2025 - Present • 9 mos

Founder & Lead Full-Stack Engineer behind a production AI SaaS platform for invoice automation and revenue recovery. Architected and developed the system end-to-end: multi-tenant backend, secure PostgreSQL database with RLS, Stripe subscription lifecycle, real-time financial dashboards and async event processing. Built AI agents for voice, email and operational workflows that analyze customer data, trigger automated actions and generate next-best-action insights. Implemented complex integrations (payment providers, external APIs, webhooks), background jobs, retry logic, audit logs and role-based access. Designed the product for real business usage with scalability, observability and performance in mind. Tech stack: TypeScript, Node.js, React, Supabase, PostgreSQL, Edge Functions, LLM APIs.