Vulkan was primarily designed to allow issuing batch based (queue) validated instructions sets, issued from multiple threads. Lessons learned from OpenGL ES 2.

Vulkan was primarily designed to allow issuing batch based (queue) validated instructions sets, issued from multiple threads. Lessons learned from OpenGL ES 2.0 showed only a subset of techniques is needed, hence the API is smaller. Shaders are precompiled. Smaller, simpler driver.