Software engineering · Rio de Janeiro, Brazil — remote
Patrick
Arinelli
Patrick Arinelli is a senior software engineer and systems architect with 9+ years of experience, specialized in Brazilian payments infrastructure — Pix, boleto, and direct integrations with Banco do Brasil and Santander — and in AI-orchestrated systems with LangGraph. Founder of Cérebro Amigo, an AI mental health platform. He builds business-critical systems in .NET, Go, TypeScript, and Python for fintechs and SaaS companies.
Background
Patrick was the first developer at Fradema Consultores Tributários, a Brazilian tax consulting firm, where he built the company's technology foundation from the ground up: five CRMs, a ticketing application, microservices, automation tools, AI-powered workflows, and banking integrations serving more than 6,000 clients.
He now works as an independent contractor on payments, fintech, SaaS, and AI products, working remotely from Rio de Janeiro in English and Portuguese. Core stack: .NET/C#, Golang, TypeScript/Node.js, Python/FastAPI, PostgreSQL, Azure, AWS, Kubernetes, LangGraph, and LangSmith.