Houkai Sekai no Mahouzue Shokunin

Kenshi Oori is a man who has lived solely by his ingenuity. That has not changed even as civilization has collapsed. One day, a swarm of magical meteorites rained down on Earth, robbing the planet of all its electricity. Advanced society which relied on electricity collapsed in an instant. As the world fell into unprecedented chaos, Oori leisurely shaped one of the meteorites and fashioned a magical wand. ...That's right. Humanity lost its electricity but gained magic in return. In a crumbling world where electronic devices no longer work, Oori's ingenuity, resulting in sophisticated creations comparable to precision instruments, could be the key to saving the world...!? (Source: Kadokawa, translated)