You run your SQL-centric infrastructure for 10 years and slowly starting to note you can’t do this way anymore – everything is getting too expensive but your business requires things which are simply impossible without radical changes. This is exact situation we had 2 years before. So we’d like to show our experience: - Why and how we came into Big Data? - Why we choose Apache and Hadoop? - What to do and what is already done? - What lessons were learned? - Hadoop and relational databases: fight or synergy? - Reactive Big Data manifest.