Barry Smyth is a data scientist. Early on in the outbreak, he was among the first to realise the importance of looking closely at the number of excess deaths in the population, as revealed by website Rip.ie, to track the true toll of the virus. Since then, he has written about the nature of lockdown measures imposed across Europe, as revealed through data. Which countries are strictest, and what happens to the virus when people start moving about again? Barry talks to Deirdre Veldon about what the data reveals. Barry Smyth holds the Digital Chair of Computer Science in University College Dublin and is a Director of the Insight Centre for Data Analytics.