[jamestimmins]

You're not working with a 10x engineer. It sounds like you're working with someone who may think they're a 10x engineer, but they're likely just reducing the effectiveness of the rest of the team. Hopefully your company/team's management is aware of the distinction. If not, you and the team need to communicate this to them (in a tactful manner).

I've worked with people who were truly 10x engineers and others who just thought they were 10x engineers. The actual ones did this by succeeding in the context of the broader team. The ones deluding themselves just made everyone else miserable, and then left messes to clean up when they left.

[updateYourMind]

I think they are different definition of 10x engineer and OP’s definition is someone who writes a lot of code and understand the stack.

[jamestimmins]

Perhaps, but I've never heard of a definition involving someone who writes "really bad code".

[updateYourMind]

OP is not saying they’re the one who are responsible for the bad code