Armstrong founded Coinbase in 2012 and is still its chief executive, through a 2021 direct listing and the whole arc from a Y Combinator startup to a public company with thousands of employees. That is an unusually long single-company operating record for someone whose advice Management Craft cites, and it is the reason to weight him: he has hired executives repeatedly, in the same company, across an order-of-magnitude change in scale, and has had to live with each of those hires afterward.
His relevance here is narrow and documented. In “How to Hire Executives” (2017) he lays out a sequence for executive hiring whose first step, before the hiring committee and before drafting the mission/outcomes/competencies document, is to speak with three great practitioners in the function you are hiring for. That is the Calibration Call, described independently and years before it had that name, and it is the closest thing in the roster to a written operating procedure rather than a remark. What his word carries weight on is the practice of hiring executives inside a fast-scaling company; he is not a researcher, and the claim rests on his record rather than on evidence he collected.