What was broken In Apache Stateful Functions, the routable Kafka ingress had no policy for malformed records. A record with a null key (there's no function instance to route to) threw inside the deserializer. A tombstone (null value, normal on compacted topics) blew up as a bare NullPointerExce...
Source: [Dev.to](https://dev.to/okazimirov/one-bad-kafka-record-shouldnt-crash-a-flink-stateful-functions-job-117)