Event-Driven Serverless Patterns That Scale on Azure

Serverless hit its awkward teenage years somewhere around 2022. In 2026, it is grown up: the patterns are settled, the tooling is boring (good), and event-driven architectures on Azure genuinely scale when you build them right. Here are the patterns that actually hold up. The three building blocks Event Grid — cheap, low-latency, pub/sub for reactive workflows Service Bus — durable, ordered, transactional messaging for business logic Event Hubs — high-throughput streaming for telemetry and logs Use all three. They are not competitors; they are different instruments. Patterns that scale 1. Grid → Function → Bus Event Grid fans out a lightweight notification to a Function. The Function does the minimum work needed to enqueue a durable command into Service Bus. Keeps the hot path fast and the business path reliable. 2. Outbox → Event Grid Write to your database and to an outbox table in the same transaction. A tiny worker drains the outbox to Event Grid. You get exactly-once-ish semantics