The release of the .NET SDK allows developers to write workflows in C#, adding to the existing support for Go, Java, Python, and TypeScript. This post provides a high-level overview of Temporal .NET's features and its development challenges. It demonstrates how to implement an activity and a workflow using C#, as well as running a worker and executing a workflow. The SDK ensures deterministic execution by creating a custom TaskScheduler and asks users not to use platform threading/async outside of the deterministic scheduler. Future enhancements include source generation, analyzers for detecting invalid calls in workflows, and support for the new TimeProvider API.