Drinking too much coffee while maven builds and deploys your service? Jealous of how your FrontEnd mate just press F5 to 'deploy' his/her changes? Mastered the red-green-refactor workflow and want to know what is the next step? Our Lisp grandfathers knew how invaluable was the immediate feedback that a Read-Eval-Print Loop (REPL) allowed during development and now Java 9 will have one. Perhaps you have read that a REPL is useful for 'playing around' or for 'small code snippets', but this is far from true. In this presentation, you will learn how with a REPL you can have a better and more productive developer workflow by building a Tomcat service, one bit at a time, without having to build, compile, package or deploy it. Demo will be done with a Clojure REPL but no previous experience with Clojure is needed.