At Allegro, you can sell items at a fixed price (buy now) or at auction. Auctions are still a popular sales format, especially in categories such as antiques and art or clothing. So far, buyers fighting for an item had to refresh the web page in the last seconds of the auction to verify that the offer had not been overbid. This made bidding difficult and less fun. Last year real time bidding process for all mobile users was introduced. In this article I want to show how to create a simple application that provides real-time bidding, based on Allegro auctions. We will use WebSockets, SockJS and the latest, third version of Vert.x. We will create a frontend for fast bidding that communicates with a microservice written in Java 8 and based on Vert.x.