Beyond Webhooks: The Future of Scalable API Event Delivery ? Phil @leggetter Hookdeck API Days / New York / 14 May, 2025

What are Event Destinations and Why It’s Time to Move Beyond Webhooks Phil @leggetter Hookdeck API Days / New York / 14 May, 2025

Brief History of Webhooks ● ● ● 2007 Jeff Lindsay creates “web hooks” Simple HTTP callbacks for real-time notifications Examples: GitHub, Stripe, Shopify, Twilio

Webhook Producer Challenges ● ● ● ● ● Scalability of Delivery Reliability & Retry Complexity Monitoring & Observability Customer Support Load Risk to Customer Infrastructure

Examples of Reliable Outbound Webhook Infrastructure https://hkdk.link/edc

Webhook Consumer Challenges ● ● ● ● ● Reliable Inbound Infrastructure Opt-In and varied Webhook Endpoint Security Inbound Processing Logic: Handling Retries & Idempotency Debugging & Observability Testing & Development Workflow

Event-Driven Architectures - Internal & External ● ● ● ● EDA = microservices = AWS, Azure, or GCP. Critical events also come from external services (e.g. Stripe, Shopify, Twilio) via inbound webhooks. Your architecture must account for both internal and external events. Why havenʼt we applied the same rigor, tools, and patterns to external event delivery?

How Leading Platforms Are Rethinking Event Delivery

Twilio Sink

Shopify “Webhooks”

Stripe Event Destinations

Introducing Event Destinations ● ● ● ● A modern event delivery model, inspired by Stripe, Shopify, and Twilio Supports delivery to many destination types — HTTP, queues, streams, and event buses Focused on reliability, scalability, and developer experience We’ve created a set of open-source guidelines have a conversation and assist adoption eventdestinations.org

Event Destinations: For API Platforms (producers) ● ● ● Improved reliability: Delivery to durable, fault-tolerant services (e.g., EventBridge, Hookdeck, Pub/Sub, Kinesis) Increased efficiency: Offloading retries, buffering, and failure handling to destination infrastructure Required security: Event destination types that require auth are an improvement on webhooks

Event Destinations: For Developers (consumers) ● ● ● Integration flexibility: Choose how and where to consume events — webhooks, queues, or event buses Simplified infrastructure: Remove the HTTP ingestion layer Improved DX Better observability, fewer ingestion issues, and improved integration with existing tools

Event Destinations: A Model Inspired by Practice ● ● ● ● Real-world patterns from Stripe, Shopify, and Twilio Delivery to Amazon EventBridge, GCP Pub/Sub, AWS Kinesis, and more Community-led effort to formalize and share modern event delivery guidance eventdestinations.org / github.com/hookdeck/event-destinations

Event Destinations Guidelines: Required ● ● ● ● At least two event destination types, including webhooks Automatic delivery retries with exponential backoff APIs to create, update, and delete destinations Alerts for destination failures eventdestinations.org

Event Destinations Guidelines: Recommended ● ● ● ● ● ● At-least-once event delivery guarantee Event topics and topics-based subscriptions Auto-disabling of failing destinations after too many failures Developer UI to configure destinations & inspect events Manual retries via UI or API Filtering based on payload content eventdestinations.org

When to Consider Event Destinations ● ● ● ● Handling increasing scale and subscriber volume Experiencing frequent webhook failures or retries Reducing operational burden from delivery management Supporting customer integration needs

Outpost: Event Destinations Reference Implementation - outpost.hookdeck.com

The Future of API Event Delivery ● ● ● ● ● Event Destinations are shaping the future of API event delivery Move beyond webhooks to scalable, resilient infrastructure Supports modern architectures and developer expectations Join the Event Destinations Initiative and help define what comes next Outpost: open-source Event Destinations implementation eventdestinations.org outpost.hookdeck.com

Thanks & Questions Phil @leggetter Hookdeck API Days / New York 14 May, 2025