CHESS is an automated tool from Microsoft Research for finding errors in multithreaded software by systematic exploration of thread schedules. It finds errors, such as data-races, deadlocks, hangs, and data-corruption induced access violations, that are extremely hard to find with current testing tools. Once CHESS locates an error, it provides a fully repeatable execution of the program leading to the error, thus greatly aiding the debugging process. In addition, CHESS provides a valuable and novel notion of test coverage suitable for multithreaded programs. CHESS can use existing concurrent test cases and is therefore easy to deploy. Both developers and testers should find CHESS useful. The CHESS architecture is described in this technical report. Here, we meet some of the researchers behind CHESS, Madan Musuvathi and Shaz Qadeer. Joining in the conversation are two software test engineers extraordinare, Chris Dern and Rahul Patil. Chris and Rahul use CHESS as part of their daily routine of finding bugs in the various technologies that power Microsoft's Parallel Computing Platform. Tune in and learn about this great technology from the folks who know it best.