Joao Barros contributed to the epilot-dev/sdk-js repository by enhancing the Customer Portal SDK to support new OTP-based journey features and improve email template management. He introduced an optional field for journey login OTP email template IDs, aligning the client with evolving API specifications while maintaining backward compatibility. Joao updated OpenAPI definitions and synchronized the SDK with the latest API contract, refining timestamp formats and adding support for new messaging flows. His work, primarily using TypeScript and OpenAPI, focused on API integration and contract adoption, resulting in a more reliable developer experience and smoother onboarding for customers integrating the portal.