Don't give coding quizzes if they can provide better evidence of their ability.
It's unfair in the least, rude at the worst to pigeon-hole "senior" programmers into scenarios / pop quizzes.
Let them show off recent personal projects. They'll probably have no problem spending a weekend hacking on something they're passionate about.
Be a serious employer:
Convince the best programmers (whatever that means) why they should reorganize their life around your business:
- Pension plans / job security are nice. It's a good motivator to know that there will be an annuity when they're 60 / 65 and would rather spend time with their family.
- Union contract (or something comparable) or a labor system with robust employee rights and unemployment insurance. It's pretty unfair in the US with at-will employment.
- Have strong financials. Be a business that'll be around in 10 years. Can your business keep paying employees if it's in the red for a year?
If you don't offer the above: Why feel deserving of the best?
I'm being facetious on the above points: It's tech, it's a fast cycle and inherently unstable. But when orgs talk about hiring - it irks me to see the entitlement employers have when they have little investment in the welfare of employees as persons (and families)