I lead machine learning in the AI department at Wargaming, where I’m building the bot AI for World of Tanks: HEAT. Day to day that means designing the systems behind how bots read a battle and decide what to do, setting the technical direction, and making sure the whole thing holds up once it’s live. I specialise in recommender systems and in evaluating them properly. I’m a bit obsessive about A/B testing and about knowing whether a change actually helped, not just whether it looked clever offline. In a live, adversarial game, that gap turns out to be most of the problem.