How Slack builds a reliable messaging platform.
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UnlockOver 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 cookbook deployments and safer…
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 workspaces using non production data to find…
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 architecture. We didn’t just want…
Excerpt By 2024, Slack& 8217;s data platform had accumulated 700+ SSH based operators orchestrating critical data pipelines. We& 8217;re talking daily search indexing that processed terabytes of data, analytics jobs powering business intelligence, the whole shebang. Every single one of these jobs required direct SSH…
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 long time spans. We present a range of…
The Problem: Legacy Tooling and Its Limitations Currently, Slack utilizes a hybrid approach to network measurement, incorporating both internal (such as traffic between AWS Availability Zones) and external (monitoring traffic from the public internet into Slack’s infrastructure) solutions. These tools comprise a…
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 by bringing calm, consistency, and…
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 our primary responsibility during on…
