Keynote Talk

Thumbnail Image

Mark Harman

Facebook and University College London, United Kingdom

Thumbnail Image

Silvia Sapora

Facebook, United Kingdom

AI techniques for Simulating Behaviour using Facebook’s WW Social Media Simulation System

Abstract: This talk describes Facebook's development of WW, its cyber-cyber digital twin, and, in particular, the way it uses artificial intelligence techniques for training bot behaviours. WW is a simulation of Facebook user behaviour on the real Facebook platform, which Facebook uses to test and optimise its products. There are inherently many foundational scientific challenges that come to the fore when attempting to safely, reliably and effectively simulate user behaviours at scale. The keynote talk will cover some existing practical and scientific work at Facebook, as well as outlining open problems and challenges for the research community for this research agenda at the intersection of AI and SE.


Mark Harman is a full-time Research Scientist at FACEBOOK London, working on FACEBOOK's Web Enabled Simulation system WW, together with a London-based FACEBOOK team focussing in AI for scalable software engineering. WW is Facebook's Cyber-Cyber Digital Twin of its platforms, being built with the long-term aim of measuring, predicting and optimising behaviour across all FACEBOOK's platforms. Mark also holds a part-time professorship at UCL and was previously the manager of FACEBOOK's Sapienz team 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 2.6 billion people world wide every day. In his more purely scientific work, Mark co-founded the field Search Based Software Engineering (SBSE), and is also known for scientific research on source code analysis, software testing, app store analysis and empirical software engineering. 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.

Silvia Sapora graduated from Imperial College London with a Master’s degree in Computing in 2019. Her master thesis, centred on using Deep Convolutional Neural Networks for robotic object grasping and sim-to-real transfer of knowledge, won the Distinguished Project and the Corporate Partnership awards. Silvia has won numerous hack-a-thon programming competitions and challenges, with entries covering a diverse range of software engineering topics and applications including IoT devices, smartphones, online retail, browser-based games, eye tracking and image recognition. She joined Facebook in 2019 as a software engineer where she works on Facebook’s WW Web Enabled Simulation system. She and her co-authors have published results from this work at the 8th Genetic Improvement Workshop (GI 2020) and the 43rd International Conference on Software Engineering (ICSE 2021).