Mark Harman is a full-time Research Scientist in the London Probability team at Facebook, working on the WW cyber-cyber digital twin. Mark is also a part-time professor at UCL and was previously the manager of Facebook’s Sapienz team, which grew out of Majicke, a start up co-founded by Mark and acquired by Facebook in 2017. The Sapienz tech has been fully deployed as part of Facebook’s overall CI system since 2017 and the Facebook Sapienz continues to develop and extend it. Sapienz has found and helped to fix thousands of bugs before they hit production, on systems of tens of millions of lines of code, used by over 2.8 billion people world wide every day. Prior to working at Facebook, Mark was head of Software Engineering at UCL and director of its CREST centre. In his more purely scientific work, Mark co-founded the field Search Based Software Engineering (SBSE) in 2001, now the subject of active research in over 40 c0untries worldwide. He received the IEEE Harlan Mills Award and the ACM Outstanding Research Award in 2019 for his work and was awarded a fellowship of the Royal Academy of Engineering in 2020.