What's the best way to deal with oversmart people

A very bad translation for "ferrymans oar".

It's a story, the ferryman has the oar, he stops being the ferryman without it, the next guy having it is the new ferryman. So you just pass it on. It's a task you can never finish but only pass on.

Preaching to the choir here: work is work. Work in IT incorporates a LOT of planning ahead and questioning decisions. But this only helps when it is not for the sake of impressing or avoiding work.

Being smart means to improve dysfunctional processes.

Being oversmart amounts to complaining.

Similar to politics, the line becomes harder to draw if current processes/ideas/workflows really are dysfunctional.

As long as money is made; presumably there is work to do

When you say oversmart are you taking about people who believe they are very smart or people who are actually very smart?

Your ‘no experience’ comment makes it seem like the former. And if they are not actually smart, you can probably demonstrate their ineptitude through simple dialog and insightful problem-solving, assuming you are smarter than them.

Also I’m not sure I see a huge distinction between intelligence and experience in this industry. People who are ‘smart’ but don’t have experience tend to do really stupid things like trying to reinvent things that already exist in a better form, or design and code whole products built around a bad design, thus burying their teams in technical debt. And that’s not very smart - that’s stupid on a lot of different levels.

My humble opinion. First, I would make sure that they are actually doing something bad, since you do not describe their behaviour but your feelings about them. It is possible that a person is genuinely trying to explain something, and they are not good communicators, or they are massive experts and come off as arrogant. Sometimes we expect people to address us in a certain way, based on hierarchy at a company/age/job title. Some people do not care much for such things, and with a certain combination, misunderstandings can arise, where no harm is intended.

Assuming the behaviour is bad, it probably steams from insecurity. Some people see life as a competition, or getting a best score as an objective, or is the main way they have learned to get appreciation (from parents, teachers, bosses). Think Lisa, from the Simpsons.

I would also avoid framing everything in terms of "have you done this before", like other commenters are recommending. It is more important if someone can back their words on the present, that an appeal to authority. (have you used Angular 3.1.2.3 before?, have you studied economics?, etc.). Arguments should be evaluated on their own, even if for practical reasons in real life we use heuristics based on experience.

Finally, I do not think the right term for this is being (over)smart. Depending on the behaviour it could be lacking social skills, being arrogant, condescending, etc.