Here you are! In front of a powerful CTO of the best we-will-disturb-the-market-startup in town. You answered a job offer promising money and glory, soon they will be all yours. To warm you, the mighty CTO begins to ask you to draw a B-Tree on a shiny whiteboard. Easy peasy, you draw a wonderful tree you saw in a garden today. Then, he gives you a sheet of paper to test “your skills”.