Daniel Weber

← Notes

Cross-tenant leaks must be impossible by construction

Cross-tenant isolation hard wall

Context

A multi-tenant platform consolidates vendor stacks. One cross-tenant leak kills trust.

What went wrong

Relying on every handler to remember tenant filters does not scale. Discipline alone cannot carry that load.

What we changed

I made isolation structural: auto-scoping wrappers, schema without silent tenant defaults, explicit markers for rare global jobs, and a deploy gate that refuses unscoped access.

Result

Unscoped paths fail the build. The promise is not "we try hard." It is "this class cannot ship."

Proof