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Why did Slack go down in Jan 2021 — #6

Welcome to Learning at Lambert Labs session #6. This week, Tom Kobialka, takes us through how the popular business communication platform, Slack, suffered a disastrous outage on 4th Jan 2021 and what could have been done to prevent it.

In Today’s Learning Session:

  • The origins of the Slack outage on 4th Jan 2021 and the ensuing twitter storm.
  • Deep dive into how Slack’s app architecture works.
  • Websocket connection of clients to a message server.
  • How all regular Web API requests and messages are eventually handled by the backend server.
  • The explosive growth of Slack.
  • Slack vs. quota limits and their solution.
  • AWS VPC Peering and Transit Gateway.
  • The timeline of the outage.
  • Analysis of blame: Slack vs. AWS.
  • Q&A from our developers.

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Lambert Labs is a Python-focused software development agency based in Earls Court, London.

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