How do you (or any other similar poster) expect candidates to lookup this job post? When it comes to engineering, please mention specific tech, like you mentioned in the follow-up comment. People lookup for specific tech keywords, be it programming languages or frameworks, not just "Engineer" or other generic terms.
How's your thoughts about the collaborate with a tech company? where you can find mutliple engineers and team at one place? which is a risk free decision to hire an inhouse team and pay whether their is work or not. Indeed doing that can suggest find a right partner and pay only for the resource you hire. If there is work then pay if not then not.
I know a vendor who can helps you to fulfill this kind of need. If something would be an interesting then can help you to connect with them. Let me know.