Explore the fundamental principles of immutability in C# and .NET development through this comprehensive conference talk from NDC Oslo 2021. Delve into the world of immutable objects and their role in functional programming, while discovering how to apply these concepts to enhance code clarity, reasoning, and error reduction in object-oriented languages. Learn techniques for implementing immutable objects and collections, and gain insights on refactoring existing codebases to incorporate immutability effectively. Examine both the positive and negative implications of introducing immutability to your projects, and understand its impact on topics such as multithreaded computing, anonymous types, and entity frameworks. Gain practical knowledge on avoiding anti-patterns, leveraging builder patterns, and optimizing your use of system collections and AutoMapper.