Here is the new discussion thread for KIP-213. I picked back up on the KIP as this is something that we too at Flipp are now running in production. Jan started this last year, and I know that Trivago is also using something similar in production, at least in terms of APIs and functionality.
https://cwiki.apache.org/confluence/display/KAFKA/KIP-213+Support+non-key+joining+in+KTable I do have an implementation of the code for Kafka 1.0.2 (our local production version) but I won't post it yet as I would like to focus on the workflow and design first. That being said, I also need to add some clearer integration tests (I did a lot of testing using a non-Kafka Streams framework) and clean up the code a bit more before putting it in a PR against trunk (I can do so later this week likely). Please take a look, Thanks Adam Bellemare
