Fractional CTO
Senior technology and engineering leadership - one to three days a week, without a full-time hire.
A fractional CTO is an experienced technology leader who runs your engineering function part-time - typically one to three days a week - rather than as a permanent hire. You get architecture, roadmap, delivery and team leadership from someone who has done the job before, and a clean handover once a full-time CTO is genuinely justified.
What does a fractional CTO actually do?
The remit is a real CTO's remit, compressed into the days that matter. On a typical engagement that means:
- Own the technology strategy: a roadmap tied to commercial outcomes, and the discipline to say no to the rest
- Architecture and technical debt: decide what gets rebuilt, what gets contained, and what is fine as it is
- Lead the engineering team: direction, one-to-ones, code review and mentoring - not just advice from the outside
- Fix delivery: planning, estimation, release process and the reasons things keep slipping
- Hire: role definitions, interview panels and scorecards, including the search for your permanent CTO
- Build, buy and spend: vendor selection, contract review, and cloud and licensing costs that nobody has looked at in two years
- Security, compliance and due diligence: the technical questions an acquirer, investor or enterprise customer will ask, answered before they ask
- Answer to the board: honest progress reporting non-technical stakeholders can act on
When do you need a fractional CTO?
Almost always the same underlying situation: technology decisions are queuing behind someone who does not have time to make them. Common triggers:
- Your CTO has left, or is about to, and the team has no senior cover
- A founder is carrying every technical decision alongside running the business
- Delivery has slowed and nobody can tell you precisely why
- You have inherited a codebase - through growth, an acquisition, or a departed agency - that nobody currently owns
- A fundraise, acquisition or enterprise deal is bringing technical due diligence you are not ready for
- Your engineering team is too big to run itself and too small to justify a £150K+ permanent CTO
- A PE or VC portfolio company needs senior technical capability dropped in quickly
Fractional CTO vs the alternatives
vs a full-time CTO
A permanent hire takes three to six months to find and onboard before delivering anything, and lands at £150K+ in year one once employer NI, pension, benefits and a recruitment fee sit on top of a median £100K base salary - before equity. It commits you whether or not the work stays at five days a week. I start in days, deliver from week one, and scale up or down month to month. It is also the cheapest way to find out what your permanent CTO role should actually be before you advertise it.
vs an interim CTO
Interim is full-time cover for a gap, priced accordingly, and ends when someone permanent starts. Fractional is a smaller ongoing commitment that can run for a year or wind down in a month. If you genuinely need someone in the building five days a week, hire interim - I will say so.
vs promoting a lead developer
Often the right long-term answer, and usually the wrong immediate one: you lose your best engineer and gain an inexperienced manager at the moment you can least afford either. A common arrangement is to do both - I hold the CTO remit while coaching them into it, then hand over.
vs a consultancy or dev agency
An agency sells you delivery capacity and has no commercial interest in your team getting stronger or your scope getting smaller. You get me - one senior practitioner with 20 years of hands-on delivery - sitting on your side of the table, including on the agency contracts you already have.
How engagements work
- Cadence: one to three days a week, adjusted as the work demands
- Duration: typically three to twelve months on a rolling monthly basis
- Commercials: a day rate billed monthly as a retainer - no recruitment fee, no equity, no long notice period
- Exit built in: knowledge transferred throughout, so the role can be wound down or handed to a permanent hire without a cliff edge
The first month is deliberately unglamorous: talk to the engineers and the people they build for, read the code and the incident history, work out where the delivery time actually goes, then come back with a short list of what to fix and in what order. You should have a clear answer on what is wrong - and the first fix underway - inside thirty days.
Fractional CTO or fractional AI leadership?
They are related but not the same job. Take this page if the gap is technology leadership generally - the team, the architecture, the roadmap and the delivery - whether or not AI features in it. Take fractional AI leadership if the technology function is broadly working and the specific gap is a senior owner for the AI and automation agenda. Plenty of engagements start as one and grow into the other, and the first conversation sorts out which you are looking at.
Why Goldseam?
- Senior, every day: you get 20 years of hands-on delivery, not a junior backed by a brand name
- Still writes code: the architecture calls come from someone who will be in the codebase, not from a diagram
- Cross-industry: proven patterns from fintech, B2B SaaS, IT services and professional services
- AI-fluent by default: when AI or automation is the right answer you get a practitioner, not a referral - and an honest no when it is not
- No dependency: the measure of success is your team continuing without me
Often paired with hands-on process automation and AI consulting work.
Related reading
- What is a fractional CTO, and when does a business need one? - the long version, including what it really costs against a permanent hire
- Fractional vs full-time vs the Big Four - a side-by-side on speed, cost, commitment and what actually gets delivered
- Build vs buy vs integrate - the call that comes up in the first month of most engagements
Frequently asked questions
What is a fractional CTO?
A fractional CTO is an experienced technology leader who runs your engineering function part-time - usually one to three days a week - rather than as a permanent hire. The remit is the same as a full-time CTO: technology strategy, architecture, delivery, team leadership and hiring. The difference is that you buy the seniority you need and none of the seniority you do not.
What is the difference between a fractional CTO and an interim CTO?
An interim CTO is a full-time, temporary replacement covering a gap until someone permanent starts. A fractional CTO is a part-time, ongoing arrangement - typically one to three days a week - that can run for as long as it is useful. Interim suits a sudden departure at a company that already needs a full-time CTO. Fractional suits a company that needs CTO-level judgement but not five days a week of it.
How much does a fractional CTO cost in the UK?
Fractional CTO engagements are charged on a day rate, usually billed monthly as a retainer for an agreed number of days. Cost therefore scales with the cadence you pick rather than with headcount. Against a permanent hire there is no recruitment fee, no equity, no employer NI or benefits, and no long notice period - which is often the deciding factor for companies weighing a £150K+ all-in commitment against a few days a month.
Can a fractional CTO manage and hire my engineering team?
Yes - for most engagements that is the bulk of the value. That means setting technical direction, running one-to-ones and code review, fixing the delivery process, sitting in on interviews and writing the scorecards, and making the honest calls about who is in the right role. A fractional CTO who only advises and never leads the team is a consultant with a better title.
How small does a company need to be for a fractional CTO to make sense?
The usual range is roughly three to twenty engineers. Below that a strong lead developer plus a few advisory days often does the job. Above that the role tends to need someone in the building full-time. The clearer signal than headcount is this: if technology decisions are queuing behind one already-overloaded person, you need CTO-level cover regardless of team size.
When should a fractional CTO be replaced by a full-time hire?
When the work genuinely fills five days a week and the direction has stopped changing - usually after a funding round, a step change in headcount, or once the platform strategy is settled and the job becomes execution at scale. A good fractional CTO tells you when that point arrives, helps you write the role, and sits on the interview panel rather than quietly extending the retainer.