Senior Backend Engineer (Node.js / NestJS) – Greenfield Product

CarOnSale

Remote, Remote, Brazil
Full-time
Posted June 05, 2026

Job Description

Freelance Contract | 9–12 months
Remote from Brazil

About the Project

Castle Tech GmbH is building a new standalone product from the ground up and is looking for an experienced Senior Backend Engineer (Node.js / NestJS) to join us on a freelance basis for 9–12 months .

In this role, you will play a key role in shaping the product's architecture, backend services, and technical direction. You will work closely with frontend engineers, product managers, and stakeholders to turn ideas into reliable, scalable backend systems.

This is an opportunity for engineers who enjoy designing systems, solving complex technical challenges, and taking ownership of meaningful projects from concept to production.

What You'll Work On

  • Build and maintain scalable backend services using Node.js and NestJS
  • Design a clean system architecture for a new production product
  • Take ownership ...