Defense in depth for file uploads

No single check is enough for upload security. The useful question is which layer catches which class of failure.

Layered model

Layer	Goal
Parser limits	Protect resources early
Extension + MIME allowlists	Narrow the route to what you actually expect
Magic-byte and structural checks	Verify the content instead of the metadata
Archive rules	Handle ZIP-specific abuse
Quarantine	Avoid all-or-nothing handling for business-critical flows
Storage isolation	Keep accepted files away from executable or public paths

Where Pompelmi fits

Pompelmi covers the application-layer upload gate. It does not replace auth, storage ACLs, logging, or endpoint protection.

Continue

• File-type validation vs malware scanning
• Secure file uploads in Node.js: Beyond extension and MIME checks
• Quarantine / inspect-first-store-later workflows
• Production readiness