When developing applications using .NET Core and C#, it is important to monitor and optimize resource usage. This best practice involves keeping an eye on the resources being used by the application, such as memory and CPU, and making adjustments to improve performance and prevent issues like crashes or slow response times. There are several tools and techniques that can be used to monitor and optimize resource usage, including profiling, caching, and load testing.

Profiling is a technique that involves analyzing the performance of an application to identify areas that can be optimized. This can be done using profiling tools like dotTrace or Visual Studio Profiler, which provide detailed information about the application's resource usage, including memory allocation, CPU usage, and network activity. By analyzing this data, developers can identify bottlenecks and other areas that can be optimized to improve performance.

Caching is another technique that can be used to optimize resource usage. By caching frequently accessed data, such as database queries or API responses, developers can reduce the amount of resources required to generate a response. This can significantly improve performance, especially for applications that handle a large volume of requests. In .NET Core, caching can be implemented using the built-in MemoryCache or distributed caching solutions like Redis or Memcached.