As autonomous systems mature, the ability to test, validate, and debug them efficiently has become as critical as the underlying software and algorithms. This paper outlines an approach to enabling simulation, record and replay, and time control native to the development and validation process. The underlying application brings deterministic control, scalable recording, and simulator integration into one cohesive development workflow, enabling faster iteration, smarter testing and deployment. This approach uses a unified testing pipeline, across MiL, SiL, and HiL, supporting flexible testing and integration through interchangeable data feeds, recordings, or simulation inputs. The same application used to test in simulation can run unchanged on a vehicle, greatly accelerating iteration and de-risking deployment. Virtual time support systems allow for executing faster or slower than real time, while preserving correct behavior and deterministic timing. Built on ROS 2’s rosbag2 framework