Foundation Devices' own about page describes Jacob Johnston as "Cofounder and VP of Operations overseeing supply chain, manufacturing, and operational infrastructure".
For a company selling signing devices, that brief is closer to the security model than it sounds. A hardware wallet is only as trustworthy as the path the device took to reach the buyer, which is why Foundation states that its products are assembled in the United States and publishes the design files behind them. Supply chain is the part of the threat model a customer cannot audit themselves.
No further biographical detail is recorded here. The company's own description of the role is the source.