{
  "id": 7296823,
  "title": "Building Distributed Systems in Elixir: Part 8 — Publish / Subscribe",
  "url": "https://urgent.news/2026/09/14/building-distributed-systems-in-elixir-part-8-publish-subscribe",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-09-14T10:35:43.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/pckrishnadas88/building-distributed-systems-in-elixir-part-8-publish-subscribe-cl3"
  },
  "original_language": "en",
  "account": "In the previous installment of this series, we crafted a Worker Pool from scratch, illustrating how a coordinator process could judiciously distribute pending jobs among a pool of available workers, safeguarding concurrency and fostering demand-driven coordination. Every interaction in that system was strictly one-to-one, with the coordinator assigning a single job to precisely one worker process. However, when an event must be received by multiple independent components simultaneously, a different approach is required. Imagine a web application or distributed backend: upon a customer completing a checkout, the Inventory Service must revise stock levels, the Email Service must dispatch a confirmation receipt, the Fraud Detection Service must scrutinize transaction velocity, and the Analytics Service must log the conversion event. If the order-processing process needed to directly inform every one of those services, the system would become tightly coupled, vulnerable to failure, and challenging to extend. In this segment, we shall construct a Publish / Subscribe (PubSub) Broker from the ground up using rudimentary process primitives: spawn, send, and receive.",
  "summary": "In the previous part of this series, we built a Worker Pool from scratch. We saw how a coordinator process could distribute pending jobs one by one to a pool of available workers, strictly bounding concurrency and establishing demand-driven coordination: Job 1 ---> [ Coordinator ] ---> Worker 1 Job 2 ---> [ Coordinator ] ---> Worker 2 Every interaction in that system was 1-to-1 (point-to-point) :…",
  "key_points": [
    "Construct Publish/Subscribe Broker using spawn, send, receive",
    "Coordinator distributes jobs among worker pool in previous part",
    "Enables multiple services to concurrently receive single event"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}