[albertwang]

Sorry if it's a bit of an enterprisy-response, but please reach out! We are supporting some non-cloud commercial customers on a case-by-case basis. The reason for this is that we find the support and maintenance burden to be much higher with a non-cloud delivery model, which isn't always a great experience for either party. We also have a managed product (where the data plane resides in your environment) that may work, depending on your infra and security requirements.

Re: custom code -- our codebase is fully source-available and open to contributions, but the source+sink code going through some refactoring to make it more beginner-friendly. Depending on your consistency requirements, we also support Debezium and our own CDC format (https://materialize.com/docs/connect/materialize-cdc/) for folks who want to bring in their own data sources. (For quick prototypes, we also support csv/json/plaintext source types, as well as SQL INSERTs!)