Imports require size/format validation, defensive parsing, previews, row-level errors, and clear partial-versus-atomic behavior.

How to apply it

Generate exports asynchronously, store privately, bind them to an authorized tenant/user, expire the artifact, and audit generation/download. Document identifiers, timestamps, time zones, and cleanup across derived stores.

Worked example

An export worker creates a private object and issues a short-lived signed URL after rechecking authorization.

Common mistakes to avoid

Predictable public file URLs or assuming account deletion only removes a main database row.

Practice task

Implement this concept in the capstone. Add one positive test, one negative or failure-path test, and a short note explaining the trade-off you chose.