Distributed Fiber-Optic Sensing (DFOS) is becoming a well-known technology used in many upstream oil & gas applications. This course will help engineers and managers to plan and execute their projects, as well as navigate the value and cost of this important technology. The first chapter covers the fundamental principles of DFOS, project design and setup, fiber-optic cable types, and downhole deployment methods, as well as an introduction to DFOS data. Subsequent chapters go deeper into specific applications such as hydraulic fracture profiling and cross-well strain analyses in unconventional reservoirs. Upon completion of this course you should understand how this technology works and how to use it to optimize multi-well hydraulic fracture stimulation designs from stage level, to well level, to pad level. The content is based on learnings from more than 10 years of experience in development and execution of dozens of projects in various regions around the world.