RenderDoc's debugger is great, and before it was shot in the head Direct3D9 PIX had a world-class shader debugger. For game console development you have access

RenderDoc's debugger is great, and before it was shot in the head Direct3D9 PIX had a world-class shader debugger. For game console development you have access to world-class shader debuggers that let you step through the raw shader assembly on the GPU at the hardware level (so you can see the individual waves/threads and register values). In practice shader debugging only sucks in OpenGL (vulkan is not great, but is closer to ideal). In Direct3D it's totally fine. This is partly due to Direct3D having well-specified semantics and always having a reference rasterizer, so a debugger can use refrast to do accurate shader step-through (unless you hit driver bugs).