Connecting Pulsar and Materialize is of interest to me too and something I might try when I find time to do so. Note that Pulsar does have a Kafka compatibility layer already[0], so it might just work out of the box. If you try this I'd be keen to hear how it goes.

[0] https://pulsar.apache.org/docs/en/adaptors-kafka/

EDIT: I don't think this adaptor will work after all, it works by replacing the Kafka Java client library with its own, so is only applicable to Java applications.