Slack Architecture

Feed: Slack System Design

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High-Level Design

Upon launching the Slack client and initiating a chat message, the following operations take place:

1. The Slack client initiates a user authorization process by executing an HTTP POST request to the web API

2. In response, the server provides a snapshot of the workspace and the WebSocket URL, enabling the establishment of a WebSocket channel

3. Utilizing HTTP, the client publishes the chat message to the chat service

4. The chat service persists the chat message in the chat database and forwards it to the subscribed gateway servers via HTTP

5. Subsequently, the gateway server utilizes WebSocket to broadcast the chat message to the subscribed users

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