Rohit Singhal enhanced cross-language certificate management in Azure Key Vault by developing new SubjectAlternativeNames features across Java, Python, and JavaScript within the Azure/azure-rest-api-specs repository. He updated the Java emitter API to support PFX-to-PEM conversion and streamlined API configuration by removing redundant clientName overrides, improving maintainability and consistency. In the azure-sdk/azure-sdk-for-go repository, Rohit expanded test coverage using Go and mock server implementations, validating new certificate features and ensuring robust response handling. His work demonstrated depth in API development, SDK design, and configuration management, delivering maintainable solutions for complex certificate scenarios without introducing regressions or configuration drift.