Bilal Bach built core data management and observability features for the ExternalsManagement projects, focusing on both frontend and backend improvements. On chahidi/ExternalsManagement-fe, he developed a CandidateService using Angular and TypeScript, enabling robust CRUD operations and seamless API integration while maintaining compatibility with evolving backend endpoints. For muhsiine/ExternalsManagement-be, Bilal enhanced operational visibility by implementing aspect-oriented logging in Spring Boot, capturing detailed controller method activity for improved debugging. He also addressed Maven build and test instability, ensuring reliable CI outcomes and accelerating the feedback loop. His work demonstrated depth in REST API integration, build automation, and cross-stack debugging practices.