My advice would be to find advisors who are experts in these skills and have them screen for them, while you do everything else. Pay them for their time in cash or options. Make sure to hire senior level people first and then have them screen for these skills in subsequent hires going forward.

Finding external recruiters that are able to screen for these skills is another option, but such recruiters are few and far between and their interests may not be aligned with yours.

At Toughbyte we do tech recruitment and have helped early stage startups hire CTOs on a few occasions where I have been the one assessing their tech skills and culture fit, but this isn't something that I have yet figured out how to delegate properly to other team members.

When it comes to assessing tech skills, this blog post I wrote is worth a read: https://www.toughbyte.com/blog/how-to-effectively-assess-cod...

Other posts tagged Hiring may also be of interest.