One of the lesser-known features of Azure that I find incredibly useful is Azure Logic Apps. It allows you to create scalable workflows and integrate various systems and services without writing code. You can use it to automate processes, orchestrate data flows, and connect with both cloud and on-premises applications.

One of my favorites is Azure Functions, which is a serverless compute service. With Azure Functions, you can write small pieces of code that execute in response to events and scale automatically. It's perfect for building event-driven applications or implementing specific functionality within larger systems.

Azure Stream Analytics is another hidden gem. It enables real-time analytics and complex event processing on high-velocity data streams. You can use it to gain insights from IoT devices, logs, social media feeds, and many other sources. It's a powerful tool for processing and reacting to streaming data in near real-time.

I've found Azure Time Series Insights to be extremely valuable for analyzing and visualizing time-series data. It's specifically designed for working with massive amounts of time-stamped data and allows you to perform advanced analytics, detect patterns, and create custom visualizations. It's a great fit for IoT, telemetry, and other time-series scenarios.

Another feature that often goes unnoticed is Azure Service Fabric. It provides a high-level programming model and runtime to build, deploy, and manage scalable and reliable microservices. This allows developers to focus on writing the core business logic of their applications, while Azure Service Fabric takes care of the underlying infrastructure and scaling.