I had an opportunity to participate in the Spring I/O 2015 conference in Barcelona . I was there with some guys from my work. This was a 2-day conference. The event was mainly focused on spring-related products. It was expected Organizers say about it 2 days full of Spring, Groovy, Grails and Cloud. In general, opinions expressed in this post are based on my observations of facts and presentations which I saw. I can say that the atmosphere was good enough. My general feeling is positive. We should take into account the duration, organization, purpose and price in order to evaluate the event.