A product, and no one senior owns it
The build works, but the architecture, security and roadmap calls land on a founder who is guessing, or on whoever was cheapest that month.
Fractional CTO
A fractional CTO, without the full-time hire.
Kyln provides fractional-CTO direction for London and UK startups: senior technical leadership on committed days, from £5,000 a month for the default Fractional package. Architecture calls, hiring, roadmap and the estimates a board can trust. Led by Josh, Kyln's founder. The published price is the whole price.
Default £5,000/mo · roughly 1 day / week · 3-month minimumWhen founders bring one in
The point a decision needs an owner.
A fractional CTO earns its fee at the moment the technical decisions start to outrun the people making them. Four situations come up again and again.
Investors want a technical answer
A raise, a pilot or a due-diligence pack needs someone who can stand behind the technical story and the numbers in it.
The AI-built prototype needs direction, not just a fix
A rescue makes the code safe. What to build next, what to hire for, what to say no to, is a separate job that outlasts the fix.
A full-time CTO is premature
A senior engineering leader is £120k a year and a long commitment. Most early teams need the judgement about a day a week, not the salary.
What the direction covers
Judgement, applied to real decisions.
The decisions before they harden
The calls that are cheap to get right early and expensive to unpick later: stack, data model, auth, hosting, and where the real technical risk sits. Made deliberately, written down, explained in plain English.
What to build, and what to kill
Sequencing the work so the next thing shipped is the thing that matters, and the feature list stops sprawling. A default recommendation, and the trade-off that would change it.
The first engineers, and the contractors
Writing the first engineering roles, sitting in the interviews, and managing the freelancers and vendors already on the project so you are not the one improvising a technical judgement.
Someone to stand behind the story
In front of investors, buyers and partners, a senior technical voice that can answer the hard question, defend an estimate, and own the account of where the product is and is not ready.
After the rescue
Who steers it once it works?
A rescue fixes what the AI left unfinished: auth, data, security, deployment. It hands back software you can run. The question it does not answer is what to do with it next.
Fractional-CTO direction picks up there. The roadmap after launch, the first hires, the architecture decisions as real users arrive, and the calls that are cheaper to get right early than to unpick later. It is the same senior judgement that signs off the readiness review, kept on past it. Most founders who built with Lovable, Bolt or v0 reach this point with a working product and no one senior to own where it goes.
Proof
Direction is worth what it ships.
The judgement behind the direction is the same one behind Kyln's builds. Two are public, with the outcome numbers on the page.
Spectinga was an email deliverability rescue that recovered a roughly 30% drop in revenue. Tango took an insurer's terms-and-conditions process from months to about five minutes, built with Ford Creative, Kyln's sister studio. Named clients, named outcomes, which is more than most fractional-CTO pages put on the table.
The default
Fractional CTO. £5,000 a month.
Roughly one day a week, with a three-month minimum. Technical direction is owned across architecture, roadmap, hiring and delivery. Prices exclude VAT.
Published default · 4 days / month
Fractional CTO
Architecture decisions, roadmap sequencing, hiring judgement and delivery oversight. A weekly working rhythm and one senior person accountable for the technical direction.
When the need is different
Capacity moves only when the role is clearly smaller or larger. These are adjustments inside Fractional CTO, not separate products.
Tech Advisor
£2,500/mo
2 days / month
A senior sounding board while the founder keeps day-to-day tech ownership. Up to two working sessions a month. Recommendations, not a standing CTO seat.
Embedded CTO
£9,000/mo
7 days / month · ~1.5–2 days / week
Operating technology lead: weekly leadership presence, eng oversight, recruitment ownership and delivery-risk management. For product-led SMEs, funded teams and diligence-heavy work.
Engineering is commissioned separately through Kyln Build. Live systems are operated through Kyln Care. Fractional CTO is senior judgement and ownership, not a bucket of engineering hours.
When the work needs building as well as steering, it runs alongside a product or platform build, or a Kyln Care plan after launch, each quoted on its own. Every number sits on the pricing page, because a founder deciding whether they can afford direction should not have to book a call to find out.
Fractional CTO questions
Want to talk through the fit? Email contact@kyln.digital.
Owns the technical direction a founder can't safely own alone: architecture and stack decisions, the roadmap, the first engineering hires, and standing behind the technical story with investors and buyers. The default package is about a day a week, so you get the judgement without a full-time salary.