Platform
Sharding
Splitting a bot across multiple gateway connections, each handling a subset of guilds. Discord requires sharding once a bot passes roughly 2,500 guilds on a single connection.
Each shard owns a deterministic slice of the guild set, so an event for a given guild always arrives on the same shard. Large bots run many shards grouped into clusters across separate processes or machines.
For a server owner this is invisible until it is not: a partial outage on a large bot usually means one shard or cluster is down, which is why some servers see a bot as offline while others do not.