A COO and a chief of staff solve two different problems, so the right choice turns on which problem you actually have. A chief operating officer takes real ownership of how the company runs — process, execution, systems, and the numbers that move — with the authority to run operations day to day. A chief of staff is a force multiplier for the founder or chief executive: they prepare decisions, drive follow-through and connect work across teams, but hold no formal authority over operations. So the line is clean: hire a COO when operations have no owner; bring in a chief of staff when the founder has no leverage. Different problems, not a seniority ladder. And for a lot of scale-stage companies the honest answer is neither hire, not yet — what you need is operational ownership itself, which can arrive fractionally or through an operating partner long before a permanent C-suite salary is the right bet.
What is the difference between a chief of staff and a COO?
Both roles sit close to the top of a company, which is why they get confused — but they are built to do opposite things. A chief operating officer owns operations. In their study of the role for Harvard Business Review, Nathan Bennett and Stephen A. Miles describe the COO as the person who translates strategy into execution and carries accountability for how the organisation actually performs — the second-in-command who runs the day to day so the chief executive can work on the business rather than in it, a framing the Bridgespan Group uses too. Ownership is the operative word: a COO does not advise on operations, they run them, and the numbers are theirs.
A chief of staff is a different instrument. Dan Ciampa, writing in Harvard Business Review ("The Case for a Chief of Staff," May–June 2020), describes the role as an "air traffic controller" for the leader and the senior team — an integrator, communicator and honest broker who makes the chief executive more effective. Ciampa is explicit that the role "goes beyond the executive assistant role": it is a genuine leadership position. But its power is borrowed, not held. A chief of staff has influence, access and the founder's mandate; what they do not have is formal authority over operations. They make the founder more effective; they do not own the function.
That is the clean distinction to hold on to. A COO gives operations an owner. A chief of staff gives the founder a force multiplier. Our deeper read on the operations side sits in what a fractional COO actually does, but the headline is this: these are not two rungs on the same ladder. They are answers to two different questions.
Is a chief of staff more junior than a COO?
This is the question the search results are fixated on — is the COO higher, is a chief of staff part of the C-suite, is it a glorified assistant? The honest answer on seniority: in most companies a COO carries more organisational weight, because they hold line authority over operations and a chief of staff does not. If you are ranking boxes on an org chart, the COO usually sits higher.
But that answer is close to useless for a founder making a hire, because it measures the wrong thing. A chief of staff is emphatically not a glorified admin — Ciampa's whole argument is that the role goes well beyond an executive assistant, sitting in on the decisions that matter and holding the trust to speak candidly to and for the leader. It is a serious role for a serious operator. It is not, however, an operations-owning role, and no amount of seniority makes it one.
So the ranking question is a trap. The moment you frame this as "which title outranks which", you have started solving for hierarchy when your actual problem is capability. The better question is not who sits higher, but which role removes the constraint that is currently capping the company — and that depends entirely on what is breaking. If what is breaking is that operations have drifted without a clear owner, that is the gap we are built to stand in.
Which does a scaling founder need — and when?
Start from the symptom, not the title. There are two distinct failure states at the scale stage, and each points to a different hire.
The first is operations without an owner. The signs are concrete: delivery slips because no one holds the whole process; the same problems recur because nothing is systematised; hiring, tooling and quality decisions get made ad hoc because there is no single accountable operator. Growth exposes the gap — more volume, more people, more moving parts, and no one whose job is to make it all run. That is a COO problem. You need someone to take ownership of execution and be accountable for the result.
The second is a founder without leverage. Here operations may run tolerably, but everything still routes through the founder: they are the final sign-off, the unblocker, the connective tissue between teams, and the ceiling on the company's pace. This is the founder bottleneck, which we have written about directly in the founder bottleneck — the point where growth is capped by how much still runs through one person. A chief of staff attacks that: they prepare the decisions, drive the follow-through and hold the threads, so the founder's time and judgement reach further. That is a leverage problem, and it wants a force multiplier, not an operations owner.
Timing follows the same logic. Bring in a COO when the operational load has clearly outgrown informal control and the cost of the next mistake exceeds the cost of the hire. Bring in a chief of staff when the founder has become the single point of failure for decisions and coordination. Reach for the wrong one and you spend a senior salary without touching the actual constraint.
Do you need a full-time hire, or will fractional or operating-partner support do?
There is a third answer the recruiting industry has little reason to give you: at the scale stage, you often do not need a permanent C-suite hire at all. What you need is the operational ownership — and that can arrive without a full-time salary and a months-long search.
A permanent COO is a large, slow, high-stakes commitment. Get it right and it changes the company; get it wrong and a mis-hire at that level can cost a year of momentum and a six-figure exit. For a lot of scaling companies the need is real but the full-time answer is premature — the operational load justifies an owner, but not yet a permanent executive on the payroll. That is the gap a fractional COO or an operating partner fills: real ownership of a function, on a commitment sized to the business. "Fractional" describes the commitment, not the seniority.
The reasonable objection here is that "operating partner" sounds like a consultant day-rate dressed up in nicer language. It is a fair thing to test, so here is the line that separates them: a consultant advises and leaves you a deck; an operator owns and runs the function and leaves it running. One transfers recommendations, the other transfers accountability. If the person is not on the hook for the result — if they cannot be the owner the operations were missing — it is advice, whatever it is called. That distinction is the whole of what an operating partner is, and it is the test we would apply to ourselves.
The practical point for a founder: the choice is not a binary between a permanent hire and doing nothing. Operational ownership is available fractionally, and it is usually faster and cheaper to get right than a mis-hire you unwind a year later. Not sure whether you need a hire or an operator in the room?
Common mistakes founders make hiring a COO or chief of staff
The most common mistake is hiring for the title instead of the problem. A founder decides the company "should have a COO" because peers do, or brings in a chief of staff because the diary is chaotic — and ends up with a senior person pointed at the wrong constraint. The fix is unglamorous but reliable: name the failure state first (operations without an owner, or a founder without leverage), then hire the role that matches it.
A second mistake is expecting a chief of staff to close an operations gap. Because the role is capable and close to the founder, it is tempting to quietly load it with operational ownership it was never given the authority to hold. The chief of staff ends up responsible for outcomes they cannot command, the operations still have no real owner, and a good operator burns out in an impossible seat. If operations need an owner, give them one — with the authority to match.
The third is treating the choice as permanent and full-time by default, when the honest answer is often ownership without the permanent salary — the point of the section above.
This is the one we hold a firm conviction about, because we have done the work rather than commented on it. For an executive-led startup in our portfolio, we did not advise on operations from the outside — we took real ownership of them. Nordhaven provided funding plus a roughly twelve-month runway and ran the company's marketing, IT, compliance and finance directly, so the founders could put their attention on growth instead of holding the operation together. We ran it; we did not advise on it. That is the distinction this whole comparison turns on: a title on an org chart is worth far less than someone actually owning the function and being accountable for how it runs.
Frequently asked questions
What does a chief of staff do? A chief of staff makes the founder or chief executive more effective. They prepare decisions, drive follow-through on what has been agreed, connect work across teams and unblock people on the leader's behalf. Dan Ciampa's framing in Harvard Business Review is that they act as an "air traffic controller" for the leader and senior team — a role that goes well beyond an executive assistant, but one that carries no formal authority over operations.
When should you hire a COO? Hire a COO when operations have outgrown informal control and no single person owns how the company runs day to day. The signals are recurring operational problems, delivery that slips because no one holds the whole process, and decisions made ad hoc for want of an accountable operator. At that point the cost of the next avoidable mistake usually exceeds the cost of the hire — and what you are buying is ownership of execution, not advice about it.
Can a chief of staff and a COO do the same job? No, and asking one to do the other's job is a common and expensive error. A COO holds authority over operations and is accountable for the result; a chief of staff has influence and access but no line authority over the function. Loading operational ownership onto a chief of staff who was never given the authority to hold it leaves the operations without a real owner and a capable person in an impossible seat.
Is a fractional COO as good as a full-time one? For many scale-stage companies it is the better fit, because "fractional" describes the commitment, not the seniority. A fractional COO or operating partner takes real ownership of a function on a commitment sized to the business — faster and cheaper to get right than a permanent executive hire, and far cheaper than a mis-hire at that level. The test is ownership: if the person runs the function and is accountable for how it performs, the arrangement is doing the job a COO exists to do.
The right move is rarely the most impressive title you can afford — it is the one that removes the constraint capping your next stage of growth. If you are weighing a COO, a chief of staff or a fractional operator and are not sure which your company actually needs, that is a conversation worth having before you commit a senior salary to it.
