Episode
How Slack Rebuilt Its Search Index for 10 Million Daily Queries
- Published
- Jun 25, 2026
- Duration seconds
- 471
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Summary
Slack's search is used over 10 million times a day. But the original Elasticsearch-based index couldn't keep up as the platform grew to billions of messages. In this episode, the CTO Podcast breaks down how Slack's engineering team rebuilt its search infrastructure from the ground up — migrating from a single Elasticsearch cluster to a custom search engine called 'Search It'. We cover why they moved away from Elasticsearch, how they sharded data across hundreds of nodes, and the key trade-offs they made to keep search latency under 200 milliseconds. Lucas and Luna also discuss the human side of a multi-year migration: getting buy-in from leadership, managing developer burnout, and the moment the new search went fully live. If you're responsible for scaling a product that depends on fast, reliable search, this episode is packed with practical lessons. #Slack #SearchEngine #Elasticsearch #Scalability #Infrastructure #Migration #Engineering #CTO #TechLeadership #Architecture #Productivity #Business #Technology #FexingoBusiness #BusinessPodcast #CTOPodcast #RealTimeSearch #Backend Keep every episode free: buymeacoffee.com/fexingo