How does Rails handle large-scale schema-less or semi-structured data storage?

Rails supports semi-structured data using JSON/JSONB columns and external NoSQL systems.

Modern Rails applications often store flexible or evolving data structures using PostgreSQL JSONB columns or external NoSQL databases like MongoDB. JSONB allows indexing specific keys for performance. This approach reduces schema migration overhead but shifts complexity to validation, querying, and indexing strategies. Rails provides ActiveRecord serialization and query support for JSON fields.