# Block Bad Data with Data Quality Enforcement

Bad data gets rejected at produce time, and the producer debugs it themselves. A malformed record is blocked by a Conduktor Gateway data quality policy and routed to a dead letter topic the producing partner can read, with every validation error in the record headers. No Schema Registry required.

## What You'll Learn

- Block records that violate a data quality policy before they ever reach the topic
- Give producers access to a dead letter topic where each rejected record carries its validation errors in the headers
- Define rules with the JSON Schema specification or CEL business rules