I tend to think of overengineering of a team member as the mistake of the team leader, unless you're really hiring a solo developer then you'd better pick an experienced one.

If you communicate your priorities properly, you put real emphasis on not creating unneeded code, people aren't stupid, they wouldn't do that. Most projects don't live in vacuum, and the difference between overengineered solution and a good solution depends on outside requirements, and that's the job of the team member to keep it on track.

I could have been talking about the team leader in this case. They are fallible people too. It wouldn't be unheard of for one to to introduce Kafka, Elastic Search, React, etc, when it wasn't needed...for reasons unrelated to the task at hand. As mentioned, one reason would be to gain experience in it, or to get it pre-approved for the team to use...in some future more appropriate situation.