When Kafka Connect workers start up, they scan the classpath and module paths for connectors, transformations, and converters. This takes anywhere from 15-30sec or longer depending upon how many JARs are included. Currently, this scanning is done synchronously during startup of the Kafka Connect workers, even though the workers may not need the result of the scan.
The scanning logic should be asynchronous and should only block any components that require the result of the scan. This will improve startup time of the workers.