As vehicles honk endlessly, calling for customers in the bustling town of Mlolongo, Machakos County, John Mwangi taps a switch in his workshop’s hall, and a glass-cutting machine with a rotating blade roars to life.

As the blade begins spinning, he opens a valve on a thin pipe hovering above the cutting machine, releasing a jet of water just above the spinning blade.

Mwangi then picks up an empty whisky bottle and methodically rolls it over the rotating blade, allowing it to slice through the glass with careful precision.