Dev: This could be sooooo easily optimized...

Me: Uhm. Don't think so. What's your idea?

Dev: Just use threads.

Me: Nope. Problem requires 3 shared resources per process step, it won't be faster by threading. Shared resource will only lead to locking contention, decreasing performance.

Dev: I don't think that will happen. Can you PROOF to ME that this will happen?

Me: It was your suggestion, so you should proof me wrong. Nice try, but no thanks.

Dev: Yeah, but it's too slow and it should run faster.

Me: If you cannot find a better approach than the current one, it runs as fast as it can while providing correct results. That's not slow. That's just working as intended and designed.

Dev: Yeah, but it's still slow.

....

You know these conversations where you just wanna rip some people's face off, stick it in the shit hole they use to talk and toss them out of the window....

Yeah. Had those conversations today.