What career or industry do you think is the least affected by corruption?

This actually is a hard question. I assume it needs to be an industry that is small, doesn't have huge margins and probably is primarily manual labour.

Maybe something like blacksmithing?

I don't think the "natural properties" of a career or industry will be enough to be lowest. I think an industry or career with high oversight from many individuals and regulators. Likely something that has fucked up before, and massively.

Slot machine programmer.

regulated industry
work can be checked many times
customers (casinos) don't want to be fucked
gamblers don't want to be fucked
loads of money to be made doing things well
lots of scary people willing to drop you in a hole

Massage therapist

What are they going to do, rub you extra rough if you're a Democrat?

Not criticizing it and it depends on whether you consider it "corruption", but isn't there a large underground market of sexual services via massage?
I feel like it's one of those things that if a cishet dude says they went to get a massage, it raises immediate jokes or suspicion.
- Pretty sure there is. Went for a massage recently, and 'this is not a sexual encounter' is explicitly in the terms of service you have to sign when making an appointment.
- Sex work is work

Librarian!

Hmm... Wouldn't be so sure. Some librarians have the power to selectively forgive late fees. They can give preferential treatment depending on their mood or the politeness of the person. You might also bribe a librarian to let you take out books from the special collection.

Panhandling

Public school teachers. Not willing to extend this to admin, though.

Everything single teacher ive even heard of is doing the job because either

They love children unconditionally
They want to raise the next generation to become productive adults who are prepared for the real world
They believe that everyone deserves enlightenment
They agree with Thomas Jefferson that school is preparation for participation in democratic society

Teachers that value money over one of these things typically do not last long.

Just to be clear, most teachers are just doing a 9-5 job they are good at. But if you ask them why they are teaching instead of making actual money in some other field, you eventually drill down to one or more of these beliefs.

The entirety of society is relying on selfless people giving everything they have to teach our children, this is fucked up that they aren't payed more

Park Ranger.

Definitely not that new Jewelry store I saw at the mall the other day, Shauron's gift emporium or something like that. That place look corrupt~~ing~~ as can be, they have nine employees working there and they all look wraithlike. Do the employees ever leave the store? There is this one creepy fellow always hanging around in the corners of the store, whispering about some birthday gift he lost or something.

Nah that place is fine. I got a ring there and they basically gave it to me. It’s really high quality and I love it. It is precious to me.
- It almost like you can't put it down.

I was going to say meteorologist, but it looks like Latin times says there are some people that disagree... https://www.latintimes.com/murdering-meteorologists-wont-stop-hurricanes-forecaster-flooded-violent-threats-weather-561991

Cleaning services, can't think of any reason to bribe them

If they go into influential people's houses or into important businesses, I can think of a few reasons to bribe them to do things for you.
A lot of men in my neighborhood seem to have died while being in proximity to a "cleaning lady."
- We must live in very different places