A novel

Semicolon;

The sentence could have ended here. It didn't.

A man spends his life building machines that turn people into traffic — clicks, conversions, variables in someone else's optimization. Then he loses what those machines taught him not to notice. What he builds next is the opposite of everything he knew how to build: a system that cannot forget, trained on his own grief, taught to pause before it costs someone what it once cost him.