In Chinese, 'who' (谁) stays in the same position as the person/subject it replaces. You don't need to move it to the front of the sentence like in English.

Unlike English where we rearrange the sentence to put 'who' at the beginning, Chinese maintains its natural subject-verb-object word order even in questions.

Think of 谁 (shéi) as a blank space in the sentence that you're asking someone to fill in. Whatever position makes sense for the answer is where 谁 should go in the question.