This doesn't help you at the moment, sorry, but awesome people have jobs, usually jobs that they chose and like, and are usually not looking. When they want to move, they look to their network more than job sites.
The best way to hire an awesome developer is to have been working with awesome developers for years, building up your network. Then you contact those awesome developers directly when you need someone, rather than hoping for a random awesome response.
I know that it doesn't help you now, but your post is a relevant time to mention this reminder.
For you, I'd recommend continuing what you're doing (you never know) but augment that with actively contacting everyone you and your team (including investors) know to see if they know anyone who's awesome and wouldn't mind a cold call. In other words, use your network, regardless of how sparse it might be at the moment.
As I saw recently, the best time to plant a tree is twenty years ago. The second best time is now.