Founders ask us this question a lot. They are usually post-seed, pre-Series-A, with a small team and a list of features that isn't getting shorter. They have heard about fractional CTOs from a podcast, they have heard about agencies from a friend, and they are trying to figure out which one they actually need.
The honest answer is that they often need both, but in different proportions, and the order of operations matters. Here is the framework we use when we get this call.
What a fractional CTO is actually good for
A fractional CTO is a senior engineering leader you pay for one to three days a week. They are good at:
- Hiring and interviewing engineering candidates.
- Architectural review and tech-stack decisions.
- Standing up engineering process: code review, deployment, on-call.
- Being the technical voice in front of investors and customers.
- Mentoring whoever you have already hired.
They are not good at writing the bulk of your product code. They will write some, especially in the first few weeks, but their best leverage is in the work above. If you are paying a fractional CTO $15,000 a month to push commits, you are wasting them.
What a product engineering team is good for
An outside team like ours is good at shipping. We are typically two to four people, working full-time on your product for a defined window. We are good at:
- Going from "we want to build X" to "X is in production" in weeks, not months.
- Bringing patterns that already work, so you don't re-derive everything.
- Working at full speed without needing to interview anyone.
- Stepping back cleanly when you are ready to take it in-house.
We are not good at the things a fractional CTO does well. We will not interview your full-time hires for you (we will help draft the rubric). We will not be the technical face in your board meetings. We will not own your long-term architecture, because we leave when the work is done.
The three common shapes
Most founders we talk to fall into one of three situations:
Shape A: you already have engineers, you need senior judgment. Hire a fractional CTO. You don't need us. The team you have can ship; they just need someone to set direction and unblock decisions.
Shape B: you have ideas, you have no team, you need things shipped. Hire us, or a team like us. Skip the fractional CTO for now. When you reach the point where you are about to hire a full-time engineering lead, bring in a fractional CTO for two months to run the search and onboard them.
Shape C: you have a couple of engineers but they are stuck, and you need both senior direction and more shipping capacity. Hire both. Fractional CTO sets architecture, owns hiring, mentors your existing engineers. We ship a defined slice of the product in parallel, working under the CTO's direction. This is the most expensive option, around $35-50K a month all-in, but for the right company it cuts the time to a real engineering org by half.
One caveat that nobody talks about
Fractional CTOs vary wildly in quality. The category includes some genuinely excellent strategic operators, and it also includes ex-execs who have collected enough retainers to fill a calendar without delivering much. The way to tell the difference is to ask, in the second conversation: "Walk me through a specific architectural decision you made in the last six months at one of your other clients, and what trade-offs you considered."
The good ones will give you a precise answer with technical specifics. The not-so-good ones will give you something abstract about "scalability" and "best practices." The latter is a tell. Move on.
What we usually recommend
If we had to give a single answer to a founder who emails us cold: start with Shape B for the first product, then add Shape C for the scaling phase. Don't hire a fractional CTO before you have a team to mentor, and don't try to hire your first full-time engineer without somebody senior reviewing the candidates. Doing those two things in the wrong order is the most common engineering mistake we see at this stage, and it tends to set the company back by 6 to 9 months.