The COO role: seven types and the CEO-COO relationship

Executive overview

Most COOs don't share the same job description — the role is defined by the CEO's personality and gaps, not by the company's org chart. No two COOs are alike because each one exists to complement a specific CEO.

The central principle: the COO must be great at whatever the CEO is not. This yin-and-yang match — not a generic job spec — determines whether the hire succeeds or fails.

The right COO is not found by searching for a COO; it's found by understanding the CEO.

The seven types of COO

1. Executor — Gets the CEO's vision done on a daily and quarterly time horizon while the CEO focuses on long-term strategy. The classic behind-the-scenes operator.
2. Change agent — Brought in (usually from outside) to lead a turnaround, major pivot, or transformation. Useful when the team won't accept change from internal leadership.
3. Mentor — Supports an inexperienced or young CEO (e.g., Sheryl Sandberg at Facebook with a 23-year-old Zuckerberg). Requires the CEO to have self-awareness and willingness to be coached.
4. Other half — Fills the CEO's specific blind spots. Outward-facing CEO pairs with inward-facing COO, and vice versa. Every COO plays this role to some degree.
5. Partner — Co-leads with the CEO, often freeing the CEO from operational overload. Requires clear role boundaries to avoid stepped-on toes.
6. Heir apparent — A succession candidate who uses the COO role to prove readiness for the CEO seat. Succession is not guaranteed — it must be earned.
7. MVP — An internal star promoted to COO to prevent them from leaving. Drives retention by recognising achievement; may evolve into an heir apparent.

Common functional roles the COO plays

• Adult in the room — Historically common in early-stage tech, where a young technical founder lacks business skills. Less relevant now as tech literacy is widespread.
• Follower vs. devil's advocate — Follower executes the CEO's vision without challenge; devil's advocate deliberately challenges it. Both require strong people skills to be effective.
• Design and execution — CEO defines the what; COO figures out the how and the who. Like a homeowner (CEO) and a general contractor (COO) — neither should do the other's job.
• Integrator — In smaller companies, the COO introduces systems, accountability, and process to translate the CEO's ideas into operational reality. Most relevant at 50 employees or fewer.
• Moderator and enforcer — Builds consensus and enables honest debate across the leadership team. In larger companies, the COO hires accountable people rather than enforcing accountability directly.

Key distinctions and nuances

• A COO can belong to multiple categories simultaneously or shift between them over time.
• The visionary/integrator dichotomy (popularised by Gino Wickman) oversimplifies: strong CEOs grow their skills, and good COOs must eventually be both visionary and operational.
• Culture is the glue of an organisation — not the COO. The CEO and COO together are the source of that culture.
• Domain expertise matters in some industries (tech, engineering, automotive) but far less in others (home services).
• Searching for a COO starts with a rigorous self-assessment by the CEO, not a job description.