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    Shipyard: How We Built Slack’s Next-Generation EC2 Platform

    Slack Engineering Over the past few years, we’ve been on a journey to modernise how we run Amazon Elastic Compute Cloud (EC2) instances at Slack. In our first post, Advancing Our Chef Infrastructure, we shared how we moved from a single Chef stack to a resilient, multi-stack setup with versioned…

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    Agentic Testing: Where Agents Fit in the E2E Testing Stack

    Slack Engineering Abstract Agent-driven end-to-end (E2E) tests add a new exploratory layer to testing, but should they replace traditional deterministic tests? We ran more than 200 agentic E2E workflows using the Playwright MCP, Playwright CLI, and agent-generated Playwright tests in test…

  3. Slack AI: The Path to Multi-Cloud

    Slack Engineering In early 2023, Slack faced a foundational challenge: serving Large Language Models (LLMs) at enterprise scale with the security, reliability, and performance our customers expect. Over three years, we evolved from basic infrastructure to orchestrating a sophisticated multi-cloud…

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    Managing context in long-run agentic applications

    Slack Engineering Excerpt In complex, long-running agentic systems, maintaining alignment and coherent reasoning between agents requires careful design. In this second article of our series, we explore these challenges and the mechanisms we built to keep teams of agents working productively over…

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    How Slack Rebuilt Notifications 📣

    Slack Engineering Introduction 🔔 At Slack, notifications are how teams stay in the loop, but they can also become overwhelming when not designed with intention. Our goal was to make staying informed feel effortless. We set out to rebuild one of Slack’s most complicated systems from the ground up…

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    Streamlining Security Investigations with Agents

    Slack Engineering Slack’s Security Engineering team is responsible for protecting Slack’s core infrastructure and services. Our security event ingestion pipeline handles billions of events per day from a diverse array of data sources. Reviewing alerts produced by our security detection system is…