When people first start learning ClickHouse®, they usually focus on SQL queries, table engines, and performance optimization. But as data grows from millions to billions of rows, architecture becomes the real game changer. Today, I explored three core concepts that make ClickHouse scalable and reliable: Nodes, Shards, and Replicas. Let's understand them with a simple example. Imagine an E-Commerce Platform Suppose an online shopping platform generates: 500 million orders Billions of user events