Felix developed a production-ready Upsales CRM API integration for the NangoHQ/nango repository, enabling customers to connect their Upsales CRM accounts through the Nango platform. He implemented API key authentication, rate limiting, and pagination, ensuring secure and scalable data retrieval for larger datasets. The integration was built using TypeScript and YAML, with comprehensive documentation provided in Markdown. Felix’s work expanded the platform’s connector ecosystem and aligned with the product roadmap by addressing both reliability and scalability. His technical approach demonstrated depth in backend development and API integration, focusing on robust authentication and efficient data handling to support business requirements.