In this talk I will begin by delivering the "State of Delve" update. In similar fashion to the popular "State of Go" talk I will begin by discussing all of the exciting new features and changes that have happened over the past year, since last FOSDEM. Following that I will go into a live demo showcasing how Delve can leverage Mozilla RR in order to perform deterministic debugging. This talk will begin by introducing users to the concept of deterministic debugging and the power that comes with it. Following that I will launch into a demo showcasing how to leverage this concept to debug an otherwise unpredictable highly concurrent program. Users will walk away with immediate practical knowledge they can begin applying in their day to day debugging.