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.
Kyln provides fractional-CTO direction for London and UK startups: senior technical leadership about a day a week, from £3,000 a month. Architecture calls, hiring, roadmap and the estimates a board can trust. Led by Josh, Kyln's founder. The published price is the whole price.
About a day a week · from £3,000/mo · month to monthA 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.
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.
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.
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.
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.
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.
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.
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.
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.
Fractional-CTO direction is £3,000 a month, about a day a week, month to month. That buys judgement and direction, not a full-time engineer's 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.