Dan Vanderkam is the author of Effective TypeScript (O'Reilly 2019) and a Principal Software Engineer at Sidewalk Labs. He previously worked on open source genome visualizations at Mt. Sinai's Icahn School of Medicine and on search features used by billions of users at Google (try "population of france" or "sunset nyc"). He has a long history of working on open source projects, including the popular dygraphs library and source-map-explorer, a tool for visualizing JavaScript code size. He is also a co-founder of the NYC TypeScript meetup and blogs at effectivetypescript.com. When he's not programming, Dan enjoys playing bridge and climbing rocks near his home in New York's Hudson Valley.