database-design

Relational schema and data modelling for backend services - entity modelling, normalisation versus deliberate denormalisation, key and id strategy (UUID v4 versus v7 versus sequences), constraints, foreign keys with explicit onDelete, indexing strategy, data types (timestamptz, money, enums, JSONB), soft versus hard delete and audit tables, multi-tenancy models, naming, migrations as the schema change process (expand/contract), seed data, retention and PII classification, and scaling levers. Load when designing or changing tables, ids, indexes, constraints, or migrations.