Explore a comprehensive Scala Days conference talk that delves into the challenges of maintaining type-safety and reification in CQRS applications. Learn how to model domains as Algebraic Data Types (ADTs) while representing operations as Commands and Events. Discover various approaches to creating a cohesive, well-typed domain, including type parameters, type projection, and path-dependent types. Examine the pros and cons of each solution, and gain insights into implementing these concepts using frameworks like Akka. The talk covers topics such as behavior modeling, DSL creation, type actions, implicit scopes, and in-memory backends, providing a thorough exploration of advanced Scala techniques for building robust CQRS systems.