A content management schema that survives contact with editors: posts with an append-only revision history, categories and tags, threaded comments, a real media library, slug redirects and a double opt-in newsletter list.
Followers, feeds and direct messages modelled for read volume: asymmetric follows, one posts table for replies and reposts, narrow like rows, per-participant read pointers and notifications.
A production-shaped e-commerce schema: products with variants, inventory per location, carts, orders with snapshotted line items, payments and shipments. Open it in the editor or export SQL for six dialects.
Shared-database multi-tenancy done properly: organizations as tenants, global users joined through memberships, invitations, scoped API keys, plans, subscriptions, metered usage and an append-only audit log.
How a digital newspaper models a metered paywall: articles with revisions, the per-reader meter, plans and subscriptions, gift links, newsletters and moderated comments.