One lesser-known feature of Azure that I find extremely valuable is Azure Logic Apps. With Logic Apps, I can easily create workflows and integrate different services without writing any code, saving a significant amount of time and effort.

Azure Container Instances (ACI) is a powerful yet underutilized feature. It enables running containers on demand without the need to manage underlying infrastructure. It's perfect for scenarios where fast startup times and short-lived workloads are required.

Azure DevTest Labs is often overlooked but can be a game-changer for teams working on development and testing environments. It allows developers to create and manage reusable VM templates, saving time and resources in maintaining dedicated environments for each project.

Azure Key Vault is another amazing feature that often goes unnoticed. It provides a secure way to store and manage cryptographic keys, secrets, and certificates used by your applications. It allows me to centralize the management of sensitive information and ensure strong security practices.

Azure Service Fabric is a relatively unknown gem for building microservices-based applications. It provides a robust platform for deploying and managing scalable and reliable services, making it easier to build distributed systems.