If you’ve been spring boot for a while, you’re probably familiar with Spring’s bootJar functionality that lets you create a new executable “fat jar” with all its dependencies pre defined. However, while I was building a kotlin app using http4k, which doesn’t come with any such built in tooling I had to resort to using the shadowJar plugin to build a fat jar. However post deploy, the app stopped starting up and I noticed the following error in the logs: