Developed a fully functional Invoice Management System for the KYH-Net23/Rika repository, delivering a user-friendly interface for creating, editing, viewing, and deleting invoices with robust validation and admin-controlled access. The project focused on end-to-end invoicing workflows, implementing frontend form validation and backend CRUD operations to ensure data integrity and security. Addressed validation and authorization edge cases, resulting in reliable and auditable billing processes. Utilized React, React Router, and JavaScript to integrate API-driven features and maintain code quality through incremental, commit-driven delivery. The work enabled faster billing cycles and scalable invoicing, aligning with best practices in frontend development and DevOps.