Glossary term
What is Sharding / Partitioning? Meaning for developers
Splitting data across machines. Example: Users 1–1M on shard 1, 1M–2M on shard 2.
Learn it properly · System DesignLesson 25: Sharding: Splitting Data Across MachinesIndexes tuned, biggest server bought, replicas added — and the primary still drowns in writes. How sharding splits one dataset across machines, the four strategies, how to pick a shard key, and the hard problems it creates.