AWS DynamoDB best practices for table design and data modeling. Use when designing DynamoDB schemas, choosing partition/sort keys, creating secondary indexes, modeling relationships, handling time series data, or optimizing query patterns. Triggers on tasks involving DynamoDB table creation, key design, GSI/LSI configuration, single-table design, adjacency lists, write sharding, or capacity planning. Does not cover DynamoDB SDK/API reference or CloudFormation/Terraform resource definitions.