diligent

quietly and steadily persevering especially in detail or exactness

Prosecuted with careful attention and effort; careful; painstaking; not careless or negligent.

Latin 'diligens' meaning loving carefully

“The footman was diligent; the champagne corks feebly recalled the file-firing at Richmond. "We'll drink to what we might have been, Dick," said the enchantress.”

— George Meredith, Complete Project Gutenberg Works of George Meredith

“Boxer has been compared to Alexey Stakhanov, a diligent and enthusiastic role model of the Stakhanovite movement.”