I like most about hazelcast jet was its ability to process large amount of real time streaming Data without any lags or bottlenecks from our application side. There were some minor issues related to this product but nothing major i would say it's overall good thing if you are looking forward to use your infrastructure for handling Streaming Real Time Applications using Java Language. We needed an Infrastructure Engine/Platform where we could handle Large Amounts of Streamed Data at High Speed while having very minimal lag times between sending request & receiving response back by user end.