I'm not sure this is exactly what you're looking for, but here are the ones I could think of. Though just be advised, just because I'm listing them doesn't mean I necessarily liked them all, but that doesn't mean you won't! :)
Forest (mountain rescue squad)
Smile, You (car safety engineer/designer)
Her Private Life (art gallery manager)
Big Issue (paparazzi -- I know journalism is often covered, but these guys are a bit morally ambiguous and often use their photos as blackmail material, so I thought it was pretty refreshing)
Search: WWW (web portal designer/manager)
Chocolate (hospice chef)
The World That They Live In (drama directors -- same as with Big Issue -- this was quite an intimate and honest/raw look at what drama productions are like)
A Piece of Your Mind (classical music sound engineer)
Strongest Deliveryman (<-- 'nuff said)
My Holo Love (glasses company manager, though it's not the main focus of the drama)
XX (bartender)
Another Miss Oh (foley artist -- highly recommend)
Fight For My Way (wannabe announcer & MMA fighter)
It's Ok, That's Love (psychiatrists -- this is something that has been trending recently, but I think this drama shows much more flawed, real, and interesting characters than your typical drama has)
Just Between Lovers (architectural model maker & construction worker -- highly recommend, but be warned: it's very heavy)
Ex-Girlfriend Club (webtoon author & film producer)
Ho Goo's Love (female professional swimmer)
Radio Romance (radio producer)
Risky Romance (endocrinologist)
Secret Garden (stuntwoman)
Sweden Laundry (laundromat)
Twelve Nights (female photographer & male dancer)
When the Weather is Fine (bookstore owner & cello teacher)
Your House Helper (male housekeeper)