> I'm curious if anyone has found any serious performance benefit from using a Span<T> or a "public readonly record struct" in a .NET CMS This response is not

> I'm curious if anyone has found any serious performance benefit from using a Span<T> or a "public readonly record struct" in a .NET CMS This response is not directly answering that "in a .NET CMS" part of your question. I'm just trying to say how to think about when to worry about optimizations. These sorts of micro optimizations are best considered when your are trying to solve a particular performance problem, particularly when you are dealing with a site that is not getting a lot of hits. I've experienced using small business ecommerce websites where each page load takes 5 seconds and given up trying to buy something. In that case profiling the site and figuring out the problem is very worth while. When you have a site getting a lot of hits, these sorts of performance optimizations can help you save cost. If your service takes 100 servers to run and you can find some performance tweaks to get down to 75 server, that may be worth the engineering effort. My recommendation is to use a profiler of some type. Either on your application in aggregate to identify hot spots in in search of the source of a particular performance problem. Once you identify a hot spot, construct a micro benchmark of the problem in BenchmarkDotNet and try to use tools like Span<T> to fix the problem.