Entity-Attribute-Value model is often called “anti-pattern” by the criticism. And probably they would be right if one misses to read the “Handle with Care” label on it. Enthusiastic inexperienced developers would easily compromise the benefits of relational DB but the coin has yet another side. Hierarchical object with thousands of properties, unknown schema, flexibility and millions of records. As always – we have to sacrifice one thing in order to win another. Then all it comes to priorities and ability for decision making. At this lecture you will not get a step-by-step manual but instead get ideas for how to build one for you. A challenge, a proof of concept, hard work and successful project for millions – that is the story to share.