A mentor at Celgene advised that the best path to becoming its CFO was to leave and first become a public company CFO elsewhere. Large companies often prefer external candidates with proven executive track records for top roles, a credential that is difficult to gain by climbing the internal ladder.

Moving from a large corporation to a startup requires blending foundational knowledge of scaling processes with newfound resourcefulness and risk appetite. This transition builds a holistic business muscle, not just a product one, by forcing leaders to operate without endless resources or established brand trust.

The transition from a leadership role at a large pharma company like Gilead to a biotech CEO involves a massive shift in scope. Instead of managing one large function with a large team, a biotech CEO is hands-on with every aspect of the company, from science to finance.

The distinction between a 'big company' and 'small company' person is irrelevant. A founder's mindset—hustling to bring new ideas to life and driving outcomes—is equally applicable and valuable in a large corporation as it is in a startup.

While startups must be nimble, analytical processes from large corporations are invaluable. The key is applying the same rigorous thinking to decision-making but compressing the timeline. Having prior experience with similar situations allows leaders to make informed choices more quickly.

Ron Cooper credits his success not to being a "scaling guy" at Bristol-Myers Squibb, but the "fix-it guy." Being deployed to turn around struggling business units across different geographies and therapeutic areas provided the multicultural, problem-solving toolkit essential for navigating the constant challenges of leading a biotech startup.

The transition from a resource-rich environment like Novartis to an early-stage biotech reveals a stark contrast. The unlimited access to a global organization is replaced by a total reliance on a small, nimble team where everyone must be multi-skilled and hands-on, a change even experienced executives find jarring.

Luba Greenwood argues that unlike in tech, many biotech CEOs lack P&L experience. In today's cash-constrained market, CEOs need to be able to build financial models and understand finance deeply to be effective, a skill she personally developed after transitioning from law and science.

While success is celebrated publicly, some of the best leadership happens privately when a CEO makes the tough, candid call to shut down a program or company due to unfavorable data. This "truth-seeking" decision, often against their personal interest, is a hallmark of excellence.