This five-day expert led course provides an in-depth exploration of Apple operating systems, aligned with Jonathan Levin’s OS Internals trilogy. It focuses on Darwin 25, macOS “26” (Tahoe), and iOS “26”, combining theoretical insight with extensive hands-on exercises. Participants will gain a deep understanding of system internals, reverse engineering techniques, and security mechanisms across Apple platforms. The course incorporates proprietary tools, undocumented behaviours, and real-world analysis techniques used by professionals in reverse engineering and security research.Learners will benefit from direct exposure to low level system components, gaining the ability to analyse binaries, interact with kernel interfaces, and investigate malware behaviour across macOS and iOS environments.