Desenvolvedor(a) Sênior Full Stack (Node.js / React) — PJ

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Desenvolvedor(a) Sênior Full Stack (Node.js / React) — PJ based in Brazil. We are looking for a senior full-stack developer to contribute directly to the evolution of a B2B SaaS product operating at scale. You will work on a production environment with high traffic, real-world external integrations, and strong requirements for performance, stability, and scalability. The role combines backend and frontend development with architecture, quality, and long-term maintainability. You will have autonomy to make technical decisions and contribute to solutions that support real business operations. Refactoring, architecture, observability, and continuous improvement are part of the day-to-day engineering culture. This is an opportunity for a hands-on professional who combines strong technical expertise with product vision and a sense of ownership.