I stumbled upon this looking into BGFX[1]. I've been looking for an abstraction layer over Vulkan and Metal and it has come down to BGFX and Diligent Engine[2]. Diligent is still a bit lower level than I'd like, so I started poking around to see who was using BGFX. I was surprised to find Microsoft is using it in their C++ version.
[1]https://github.com/bkaradzic/bgfx
[2]https://github.com/DiligentGraphics/DiligentEngine