PostgreSQL provides great support for JSON objects and every developer working with this data type should learn how to take advantage of it. Instead of going through the documentation on how to use JSON in PostgreSQL, in this talk we will use a case study to learn by example. We will also complement the usage of JSON by introducing other data types such as ARRAY. We will also review some design decisions to turn JSON objects into columns and vice versa when it's convenient. This talk will help you to axe the archaic Entity-Attribute-Value (EAV) pattern from your database.