This course offers students the opportunity to reflect on the extensive methods and techniques they have acquired and learn how to make optimal decisions based on the evidence at hand. It also provides relevant insights into the day-to-day operations of data and policy practitioners in the field and how their choices affect the work of their organisations at large. By the end of the course, students should have understood the connection between data science theory and practice and how public policy can employ them for better decision-making, have networked and engaged with professionals from different sectors and obtained a better vantage point on their career paths. The course begins with a formal introduction to decision theory and how to reason under a multitude of choices, information and data sources, especially when the decision taken will have real-world consequences. Following this, the second part of the course will feature practitioners from government, industry and non-profit organisations to explain in detail how these principles and theories are applied in reality. Depending on availability, the course seeks to include a range of speakers to generate a lively discussion on how data-driven decision-making is implemented in different scenarios and professional settings.