Why does the default flip at Series B?

Because the job becomes full-time in fact, not just in title. Post-Series B, product leadership carries a scaling team (often 15+ across product and design), a pricing and packaging surface with real revenue consequences, a board that expects product strategy as a standing agenda item, and cross-functional coordination — sales, CS, marketing, engineering — that consumes hours fractional models don't have. Twenty hours a week of excellent judgment can set the direction; it cannot also be in the rooms where a Series B company's execution gets shaped. Pretending otherwise is how fractional engagements at this stage disappoint — and I'd rather lose the engagement than the argument.

What are the three scenarios where fractional is exactly right?

The search bridge: the full-time search takes 4–8 months done properly; a fractional CPO holds strategy, keeps the roadmap honest, and — the highest-value version — helps run the search and onboards the hire. The pre-hire diagnostic: before committing $250K+ plus equity, a 90-day fractional engagement answers what kind of CPO you actually need (growth-led? platform? enterprise?) — mis-specifying the profile is the most expensive way to learn it. The recovery: a CPO departed or a search failed, the team is drifting, and the choice is a rushed hire or a stabilized function while you search properly. In all three, the engagement has a defined exit — that's what makes it a bridge and not an avoidance.

What does the bridge cost against the alternative?

A six-month fractional bridge at my rate is $48K — against the cost of the alternative paths: a rushed CPO mis-hire (a year of executive comp plus the strategic drift, comfortably mid-six-figures), or a frozen function during an 8-month search (every product decision queued or defaulted). The bridge also compresses the eventual hire's ramp: an onboarding run by someone who's been inside the strategy for six months beats a cold start by a quarter — the ROI guide covers how to measure that in leading indicators rather than faith.

How do you run the search and the bridge in parallel?

Sequence it deliberately: month 1 — the fractional diagnoses and writes the strategy document that becomes the search's job spec (specs written from a real strategy attract different candidates than specs written from a template). Months 2–5 — function runs on the bridge while the search proceeds; the fractional joins final-round interviews as the practitioner voice. Month 6 — handover: the strategy, the evidence base, the team context, delivered in weeks instead of discovered in quarters. Written exit criteria from day one keep everyone honest — the interim guide's exit section applies here verbatim.