Kirill Linnik developed a new DeliveryReport GET endpoint for the ACS SMS service in the welovej/azure-rest-api-specs repository, focusing on API specification and OpenAPI standards using YAML. He addressed type consistency by correcting the deliveryStatus field from enum to string, ensuring accurate type definitions and aligning API examples and documentation versioning. His work included updating the OpenAPI specification with a 2025-08-01-preview tag and refreshing related JSON files and README content. By enhancing documentation clarity and version alignment, Kirill improved API completeness for customers and reduced integration issues, demonstrating a thorough approach to API design and maintenance within the project.