Modern collaborative methods such as event storming bring experts and development teams together. "(Functional) Domain Modeling" goes one step further and enables collaborative work on code. In this workshop you can try it out "hands-on". Our PO explains the domain and we work out a common understanding in event-storming. Then we model the domain using the TypeScript type system. This enforces invariants already at compile time and experts can give feedback on the code directly. The goal of the workshop is not only to use the TypeScript type system for modeling, but also to practice communicating with POs, Requirement Engineers, customers and other subject matter experts!