Publish-Subscribe (Pub/Sub)
Publish-subscribe is a messaging pattern where publishers send events to a topic without knowing subscribers, and multiple subscribers receive copies independently. It enables broadcast notifications, cache invalidation, and loosely coupled microservices.
Technical Architecture & Deep-Dive
In pub/sub, the broker routes each message to every active subscription on a topic. That differs from a work queue where one consumer typically owns each message.
Cloud pub/sub services pair well with webhook ingress: an edge handler validates Stripe or Paddle events, publishes to a topic, and separate workers update CRM, email, and analytics in parallel. Idempotent consumers prevent duplicate side effects when providers retry deliveries.
Key Architectural Benefits
Implement Publish-Subscribe (Pub/Sub) at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:What is the difference between pub/sub and a message queue?
Pub/sub broadcasts to all subscribers on a topic. A queue usually delivers each message to one worker for task processing.
Related Architecture Concepts
A message queue is middleware that stores messages until consumers process them, decoupling producers from consumers in time and scale. Producers publish to a topic or queue, and workers pull or subscribe to handle tasks asynchronously.
Event-driven architecture is a design approach where services communicate by producing and consuming events, such as order placed or subscription canceled, rather than calling each other synchronously. Consumers react to events independently, which decouples systems and improves resilience.
A webhook is an HTTP callback: when an event occurs in one system, it sends an HTTP POST with event data to a URL you register. Instead of polling an API repeatedly for changes, your application receives updates in real time, such as payment succeeded or ticket created events.
Microservices architecture structures an application as a collection of small, independently deployable services, each owning a single business capability and its data. Services communicate over APIs or messaging, allowing teams to build, scale, and release parts of the system separately.
Ready-to-Use Edge Recipes
Any Frontend / Mobile apps hit CORS and credential limits when calling Paddle and Supabase. Edge receives Paddle webhook and updates Supabase in one flow. Use one RealComposer edge URL with OPTIONS handling, client tokens, and vault injection.
To solve call two rest apis in parallel and return merged payload, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.