workhorse
n.a person or machine that is very reliable and does a lot of hard work. You use this to describe someone who is not flashy but gets the job done.
n.a person or machine that is exceptionally reliable and capable of performing a large amount of work. Often used metaphorically to describe a dependable employee or a robust piece of equipment.
“He is a real workhorse who never complains about long hours.”
“The company relies on her as a workhorse, knowing she can handle the most difficult tasks with ease.”
“While the newer models are more stylish, the older truck remains a workhorse, enduring the harsh conditions of the construction site without any mechanical failures.”
From Middle English werkehorse, equivalent to work + horse.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.