It carries a mix of confusion and hostility. It's often used as a "reality check" for someone who is overstepping.
Because this is a vulgar slang term rather than a product, service, or creative work, there are no "professional reviews" for it. However, in terms of its "usage" and "reputation" within Turkish internet culture,
This phrase is highly informal and contains profanity ("amk"). It is not suitable for professional or polite environments. sen kimsin - Turkish English Dictionary - Tureng
It is an effective, albeit aggressive, way to dismiss someone who is acting overly important or interfering in a conversation they weren't part of.
The phrase is a slang expression in Turkish that roughly translates to "Bro, who the f * are you?"** . It is commonly used in online gaming, social media comments, or informal group chats.
It is a classic "internet meme" response. Using it typically signals that the speaker finds the other person's presence or opinion irrelevant.

