XFaaS: Hyperscale and Low Cost Serverless Functions at Meta. - Alireza Sahraei; Soteris Demetriou; Amirali Sobhgol; Haoran Zhang; Abhigna Nagaraja; Neeraj Pathak; Girish Joshi; Carla Souza; Bo Huang; Wyatt Cook; Andrii Golovei; Pradeep Venkat; et al. (SOSP, 2023)