Marcin is enthusiast of clean coding and good design. Author of "Mockito Instant" and "Mockito Cookbook" books. Contributor to several open source projects (including Drools, Moco, Mockito). Co-author of the Groovy @Builder and ExternalStrategyBuilder in Groovy core. Author of Uptodate Gradle plugin and Spock subjects-collaborators extension open source projects. Co-founder of the Warsaw Groovy User Group. Frequently talking about microservices and organizing microservice hackathon.