This is not a 10X programmer. A 10X programmer delivers the same amount of functionality in 1/10 the time.
For me the first 10x programmer that comes to mind is Peter Norvig. This spell checker he wrote in a single flight remains a work of art:
https://norvig.com/spell-correct.html
Very few programmers would come up with something so concise and elegant yet powerful in such a short amount of time.