This presentation deals with logging in the course of mobile development, namely describing the open source logging environment built with ELK stack (ElasticSearch, Logstash and Kibana). Presentation by Igor Rudyk (Software Engineer, GlobalLogic, Lviv), delivered at Mobile TechTalk Lviv on April 28, 2015. More details - http://globallogic.com.ua/mobile-techtalk-lviv-2015-report