Duolingo runs hundreds of microservices for 130M+ monthly active users, with engineers juggling GitHub, Jenkins, Sentry, Grafana, Honeycomb, PagerDuty, Jira, AWS, BigQuery, and more. We saw a chance to connect AI tooling to all of it. That’s how local experiments by a few engineers grew into an AI Slack app used weekly by 30% of the company. It is now open-sourced at github.com/duolingo/slack-ai-agent . The MCP Journey Early Adopters (Nov 2024) In November 2024, Anthropic introduced the Model Context Protocol (MCP)—an open standard that connects AI agents to external tools. A few engineers immediately saw the potential and started wiring up MCP servers in their local editors. But setup was painful: each one required hunting down the right config and credentials, and then hand-editing mcp.json. The barrier was so high that only a handful bothered.…