# What a fractional CTO actually does — and when you need one

A fractional CTO is a senior technical leader who owns your technology direction part-time — usually a day or two a week — instead of being a full-time hire. The "fractional" part is about time, not seniority. You get the same level of judgement you'd get from a full-time CTO; you just don't pay for five days when your stage of business only needs two.

## What it isn't

It's easy to confuse the role with three things it isn't:

- **It isn't a consultant.** A consultant hands you a report and leaves. A fractional CTO stays accountable for what actually ships.
- **It isn't a contractor.** A contractor executes a defined spec. A fractional CTO decides what the spec should be.
- **It isn't a part-time employee.** You're not buying hours. You're buying ownership of an outcome.

## What it actually involves

In practice the work clusters around a few things: setting the technology and AI strategy, making the architecture decisions that are expensive to get wrong, leading or hiring the engineering team, and — if the person is any good — staying hands-on enough to write code and review pull requests when it matters. The rare and valuable combination is someone who can sit in a board meeting in the morning and ship working software in the afternoon.

> The best fractional CTOs are defined by ownership, not hours. They take the important problem nobody else owns, and make it theirs.

## The signs you actually need one

You probably need a fractional CTO when: technical decisions are piling up and no one senior is making them; you're spending real money on developers without anyone setting their direction; you have a product idea but no one who can own the build end-to-end; or you've inherited something half-built and stuck. If any of those feel familiar, the gap is usually ownership, not effort.

For a practical checklist, read [7 signs you need a fractional CTO before you burn more dev budget](/content/blog/7-signs-you-need-a-fractional-cto-before-you-burn-more-dev-budget/index.html).

If that sounds familiar, this breakdown of [why startups fail at technical decisions](/content/blog/why-startups-fail-technical-decisions/index.html) explains the pattern in more detail.

## What it costs

Day rates vary widely with experience and the value at stake. As a rough UK guide, expect senior fractional CTO work in the region of £700–£1,000 a day, often structured as a monthly retainer for ongoing leadership. The economics work because you're paying for a fraction of a senior person's time rather than a full salary, equity, and the cost of a bad hire.

## The honest test

If you can write a tight spec and just need it built, you want a contractor. If you want advice and a roadmap, you want a consultant. If you have an important, half-defined technical problem and nobody to own it through to live — that's the moment for a fractional CTO.

If you're weighing options right now, read [fractional CTO vs full-time vs consultant](/content/blog/fractional-cto-vs-full-time-vs-consultant/index.html) for a practical decision guide.