A slow interview process can cost you a strong candidate
Good people often have more than one conversation running. That does not mean you need to rush a decision, but you do need to keep momentum.
Agree who will interview, what each stage will test and when feedback will be given. If a director needs to sign off the hire, get their diary involved before the first interview.
Even when the answer is no, feedback matters. People remember how they were treated, and in specialist markets you may meet that candidate again.