Fractional CTOs are everywhere now, and mostly that is a good thing. Senior technology leadership without the full-time cost is exactly what a lot of companies need. But there is a version of this arrangement that quietly works against you, and most founders never see it coming.
It is the fractional CTO who comes attached to an agency.
Here is the problem. When a software house or digital agency lends you one of their experts to act as your technology leader, that person has two employers: you, and the agency that signs their cheque. Their advice is supposed to serve your interests. But every recommendation to bring in more of the agency's developers, to extend the agency's contract, to pick the stack the agency happens to specialise in, also serves their real boss. It is hard to serve two masters. So they don't. The agency wins, and you pay for it.
The imbalance of knowledge, used against you
This works because of a gap you already feel if you are a non-technical founder. The person across the table knows more about the technology than you do, and a good salesperson knows exactly how to use that. Account managers are trained to upsell. The genuinely well-meaning engineers get kept at a safe distance from you.
And the agency that swears it is "technology agnostic", free to pick the best tool for your job, almost never is. Everyone specialises. They have teams built around specific languages and frameworks, and they are not going to retool at their own expense to suit you. So you get steered, gently and expertly, toward the solution that suits them.
The "CTO" might be a business analyst
There is a second trap, and it is more common than it should be. An agency will tell you that all its people are top-tier experts, then put forward an average business analyst or a mid-level engineer with a CTO title bolted on. I have seen this happen more than once. The reputation of the firm is doing the talking, not the actual experience of the person you are about to trust with the most strategically important decisions in your business.
The defence is simple. Interview the individual, not the logo. Judge the specific person on their own merits, their own track record, their own scars. The reputation of the firm tells you nothing about the competence of the one human being they have put in front of you.
What good actually looks like
The fix for both problems is the same. Find someone independent, who charges you directly, with no middleman and no colleagues to upsell. Someone personally accountable, who you can meet, evaluate, and build a relationship with. Someone whose only incentive is your outcome, because that is the only thing they are being paid for.
And there is one trait worth weighting above almost all others: curiosity. A real advisor leads with questions. They dig into your business, validate their assumptions, and tell you where their knowledge comes from. If someone fires back quick, confident answers to genuinely complex questions without doing the work first, treat it as a red flag, not a sign of brilliance. The best technical advice is slow before it is fast.
One more thing, and it is the one founders get wrong most often. Engage your independent advisor early, before you hire the development team, not after. The most expensive mistakes in a tech project are made in the first few decisions: the architecture, the platform, the hiring profile. Those are made before a single agency developer writes a line of code. By the time you have a team in place, the costly choices are already behind you.
None of this means an agency is the wrong answer, or that a fractional CTO is a gamble. A well-structured fractional engagement is one of the best-value decisions a growing company can make, and I have written separately about when it fits and when it doesn't. It simply means you should know whose interests your technology leader actually serves. If the honest answer is "not only yours", you have not really hired a CTO. You have hired a salesperson with a better title.
If you want a second opinion from someone with no agency behind them and nothing to upsell, that is exactly what I do. Let's talk.
Related: Fractional CTO. Is outsourced technology leadership right for you? · Does your business need a CTO?
