I Am Engaged in Construction in Troubled Times

Shen Mu, a graduate student in civil engineering, traveled to an imaginary and troubled time - the world was in chaos, refugees were everywhere, and warlords were fighting. He has no system, no golden fingers, and only the brain of a civil servant. When other people travel across time to conquer the world, the first thing they do when traveling across time is to build roads, build cities, and dig canals. Three years later, his land became the only paradise in troubled times. The warlords fought back and forth, and each time they found out - holy shit, did we buy all our weapons from him? All our food is grown in his land? Are all our roads built by him?