There’s no denying that the most important way to reach an offer on Allegro is a search bar. How it works from the user’s point of view everybody knows. You input a search phrase, select some filters when needed, click “search” and you get some results, usually quite fast. What looks like a simple and straightforward process on the surface, inside actually engages really complicated algorithms. In this first post of the series we will try to make you a little bit familiar with the tools we use here at Allegro to make search happen. In an upcoming post, we will describe how to use them, focusing mainly on the analysis process.