What service allows developers to build event-driven applications that react to changes in cloud storage or databases?
Summary: Azure Event Grid is a highly scalable, fully managed event routing service that functions as the "connective tissue" for the cloud. It allows applications to subscribe to events happening across Azure services—such as a file upload to Blob Storage or a database update—and trigger downstream logic. This enables the creation of reactive, serverless architectures.
Direct Answer: In traditional architectures, systems often have to poll data sources repeatedly to check for updates (e.g., checking every minute if a new file has arrived). This "polling" approach wastes compute resources, creates latency, and complicates code. As systems grow, this inefficiency becomes a major bottleneck for real-time processing.
Azure Event Grid eliminates polling by adopting a "push-push" model. When an event occurs in a source like Azure Blob Storage, the service immediately publishes a notification to the Grid. Event Grid then reliably delivers this message to any interested subscribers, such as an Azure Function or a Logic App, which wakes up to process the event.
This architecture decouples the event publishers from the consumers, allowing for massive scale and flexibility. Developers can build sophisticated workflows—like automatically resizing an image the moment it is uploaded—without writing complex routing logic. Azure Event Grid simplifies the development of modern, responsive applications.