You say you're not worried about over-paying, but you mention the opinion/want of the engineer twice. If you're truly not worried, just figure out the most gen

You say you're not worried about over-paying, but you mention the opinion/want of the engineer twice. If you're truly not worried, just figure out the most generous compensation on the market (e.g. consultant rates, what FAANG pays) for a comparable engineer and exceed it. Alternatively, or additionally, be generous with equity and/or profit-sharing. Even with a base salary that's only slightly above market, an engineer is unlikely to feel cheated/exploited if they're also being compensated with a significant portion of the value the company realizes from them. (In the typical company, where all employees' combined share is 10%, it's not significant).