A good manufacturing engineer is rarely unemployed and rarely scanning job boards. They are attached to a launch, a line or a yield problem. When they do look, it is because something changed: a new boss, a plant sale, a project ending. That timing is invisible to a posting.
Postings also fail on content. Most describe the job in tool names and generic duties. An engineer wants to know the process, the equipment, the volume and the problem. A posting that says exactly what you are trying to fix gets read. One that lists ten responsibilities gets skipped.
Strong engineers pay attention to peers. They hear about openings from former colleagues, suppliers and equipment vendors. That is why direct outreach tends to work better than advertising: it arrives through a conversation about the work.
If you are hiring, make the first conversation technical. Have the engineering manager, not HR, explain the process and the problem. Move quickly after that. Engineers with options will not wait through a six-week process.
Finally, consider relocation honestly. Many process specialties sit in clusters. The best person for your plant may be two states away and willing to move if the role is clear and the offer reflects it.