Shawn Hargreaves

tl;dr;
In the next update to Windows, codenamed 19H1, D3D12 will allow drivers to use idle priority background CPU threads to dynamically recompile shader programs. This can improve GPU performance by specializing shader code to better match details of the hardware it is running on and/or the context in which it is being used.

Engineering specs for a number of DirectX features, including DirectX Raytracing, Variable Rate Shading, and all of D3D11, are now available at https://microsoft.github.io/DirectX-Specs. This supplements the official API documentation with an extra level of detail that can be useful to expert developers.

When you are the team behind something like Direct3D, you need many different graphics cards to test on.  And when you’ve been doing this for as long as we have, you’ll inevitably accumulate a LOT of cards left over from years gone by. 

This document picks up where the MSDN “DXGI flip model” article and YouTube DirectX 12: Presentation Modes In Windows 10 and Presentation Enhancements in Windows 10: An Early Look videos left off.  It provides developer guidance on how to maximize performance and efficiency in the presentation stack on modern versions of Windows.