Greg works on Zulip, the world's most productive group chat software, which is proudly 100% open source and in Python. As an engineer and manager at Dropbox he led work that helped everyone write higher-quality code faster, including the Mypy project which brought static types to Python. Previously he worked at Quora and at Ksplice, which made it possible to update your operating system without rebooting; and before that, studied theoretical computer science at MIT and Harvard.