Over the course of the last decade, the innovation and proliferation of digital technologies radically transformed existing markets and gave birth to new ones. Alongside this change the skills that firms need to compete shifted. Competition and consumer agencies similarly have expanded their capabilities to meet the regulatory demands of dynamic, digital markets. ‘Technologists’ now work at most major agencies, on cases involving data and digital markets and on innovating agency processes; and most of these agencies have reorganised to have a dedicated specialist branch or unit. Bill Kovacic, former Federal Trade Commission Chair, has referred to this technology-led transformation as ‘one of the top five developments in competition over the last three decades’. The Competition and Markets Authority (CMA) has been an early adopter and its Data, Technology and Analytics unit now has almost 50 people – and growing – across the disciplines of data science, engineering, technology insight, behavioural science, eDiscovery and digital forensics. This paper highlights how the unit has brought value to cases, and it draws lessons for how similar units can succeed. It describes five roles that technologists play in competition and consumer agencies and explains how their work contributes to cases, drawing on concrete examples primarily from the CMA’s work. It also outlines the main issues and design choices when founding a data and technology unit in an agency. The paper concludes by considering how competition and consumer work will be affected, including a potential shift from the agendas of agencies being mostly reactive and set by complaints, to being proactive and increasingly set by pre-emptive data gathering and monitoring.