The phrase "an extremely difficult job" is correct and usable in written English.
You can use it to describe a task or position that requires significant effort, skill, or perseverance.
Example: "Completing the project on time was an extremely difficult job, but the team managed to pull it off."
Alternatives: "a very challenging task" or "a highly demanding position."
"The umpires have an extremely difficult job.
He really has an extremely difficult job, and that's an understatement.
He has an extremely difficult job, he is running for higher office, his own actions have led to the probable breakup of his marriage -- and he just learned that he has the disease that killed his beloved father.
"This vote should not be seen as an endorsement of the Bush administration environmental policy, but a vote in support of a fine and honorable man who has an extremely difficult job ahead," said Senator James M. Jeffords, the Vermont independent who is the ranking minority member of the Senate Environment and Public Works Committee.
It seems to me an extremely difficult job you've got and when one looks back - there were a whole spate of these sort of inquiries in the 50s - when you look back there does tends to be, your job, your challenge is to stop yourself becoming a total irrelevance.
Brad Haddin, the Australia wicketkeeper and vice-captain, said umpires should use the reviews instead of the players while Prior, who dismissed concerns that he was struggling with an achilles problem before Thursday's second Test at Lord's, said the officials have an extremely difficult job.
"Construction is an extremely difficult business.
This is an extremely difficult task.
Nobody else really knows that it is extremely difficult job, which carries incredible responsibility, and which is emotionally exhausting.
The Met defended its handling of the siege, saying it was "very proud" of its officers and the "extremely difficult" job they did.
The danger is you're putting these women into extremely difficult jobs, with very little guarantee of success.
