# How Klaviyo uses a 192-node ClickHouse cluster for real-time segmentation and personalization

DevFeed: [How Klaviyo uses a 192-node ClickHouse cluster for real-time segmentation and personalization](<https://devfeed.tech/articles/how-klaviyo-uses-a-192-node-clickhouse-cluster-for-real-time-segmentation-and-personalization-5286.md>)

Original publisher: [Read original article](<https://clickhouse.com/blog/how-klaviyo-uses-a-192-node-clickhouse-cluster-for-real-time-segmentation-and-personalization>)

Author: ClickHouse

Published: 2025-08-05T16:55:05Z

Content type: article

Language: en

Sources: [ClickHouse Blog](<https://devfeed.tech/sources/clickhouse-blog.md>)

Topics: [clickhouse](<https://devfeed.tech/topics/clickhouse.md>), [personalization](<https://devfeed.tech/topics/personalization.md>), [real-time](<https://devfeed.tech/topics/real-time.md>), [data](<https://devfeed.tech/topics/data.md>), [Apache Cassandra](<https://devfeed.tech/topics/cassandra.md>), [Python](<https://devfeed.tech/topics/python.md>), [MySQL](<https://devfeed.tech/topics/mysql.md>)

Tags: [analytics](<https://devfeed.tech/tags/analytics.md>), [backend](<https://devfeed.tech/tags/backend.md>), [cassandra](<https://devfeed.tech/tags/cassandra.md>), [clickhouse](<https://devfeed.tech/tags/clickhouse.md>), [data](<https://devfeed.tech/tags/data.md>), [databases](<https://devfeed.tech/tags/databases.md>), [mysql](<https://devfeed.tech/tags/mysql.md>), [personalization](<https://devfeed.tech/tags/personalization.md>), [python](<https://devfeed.tech/tags/python.md>), [real-time](<https://devfeed.tech/tags/real-time.md>)

## AI overview

This article describes how Klaviyo uses a 192-node ClickHouse cluster to power real-time customer segmentation and personalization. It covers the scale of Klaviyo's event and profile data, the role of its backend data platform, and limitations in the previous architecture involving Python, MySQL, and Cassandra.

## Source excerpt

"Our customers want to identify trends in their customer base and interact meaningfully with their customers. ClickHouse powers the engine for that." Patrick McGrath, Lead Software Engineer