DynamoDB optimization: hot partitions, key design, on-demand vs provisioned capacity, adaptive capacity

DynamoDB performance depends heavily on how your data spreads across partitions. A table's data and throughput are divided among partitions by the hash of the partition key, and each partition has its own throughput limit: up to 3,000 read capacity units and 1,000 write capacity units per second. So a table can have plenty of total capacity and still throttle if requests concentrate on a few keys.