Gentrace has enhanced its platform, managing a sophisticated microservices architecture to test and evaluate AI systems at scale, meeting enterprise demands for secure, self-hosted deployments. Initially relying on Kubernetes' basic networking, Gentrace faced increased requirements for end-to-end encryption and fine-grained access control as client needs grew. To address these, Istio was integrated as a service mesh solution, providing robust security features like mTLS encryption, automated certificate management, and service visibility without altering application code. Istio's implementation was made optional, allowing customers to choose their service mesh preferences seamlessly through Helm charts. Besides achieving zero-trust security, Istio offered benefits such as simplified certificate management and enhanced observability with the Kiali visualization tool. The flexibility of the architecture allows for future enhancements and easy adaptation to customer needs, ensuring robust security while maintaining user simplicity.