In early September 2020 the NHS launched its COVID-19 app to the public. Whilst to many this may seem like an extremely simple tool, the story behind its creation is far from simple. In the first of a new series, Accenture’s Sachin Patel speaks to Mark Briers, previously the lead scientist on the app, about the expertise that went into building it, his personal experiences as a member of this high profile project and how data science helped save lives.