Career
Prior to joining Microsoft, he worked for Heathkit, on HDOS and Benton Harbor Basic. While at Microsoft, Letwin worked on a number of projects. His first project at Microsoft was writing a BASIC compiler.
He is most noted for being the lead architect of the Operating system/2 operating system on the Microsoft side, with Editor Iacobucci being the lead architect from International Business Machines Corporation"s side.
Letwin contributed much of the design and code for several core components, including the HPFS file system. While at Microsoft he had become a millionaire, with a 2000 TIME article estimating his worth at around $20 million.
