The Events Rail: Inside Atlassian's Webhook Delivery Platform

This post details the architecture of Atlassian's webhook delivery platform, referred to as the 'events rail'. It highlights the challenges of selective subscriptions, multi-tenant fairness, and the design philosophy of prioritizing delivery over latency. The architecture is a two-stage pipeline with an Events Queue and a Webhooks Queue, separating CPU-bound event matching from network-bound event delivery. Key improvements include layered fairness mechanisms and a per-surface configuration model for extensibility.