Case Studies

What this looks like in practice

Most startups don't fail because they ran out of ideas. They fail because someone made the wrong technical decision at the wrong moment — and nobody caught it in time.

A fractional CTO is senior technical leadership engaged on a part-time or project basis. Not a consultant who writes reports. Not an agency that delivers sprints. Someone who owns the technical direction of your company and is accountable for the outcomes.

Here is what that looks like in practice:

A B2C startup was paying to maintain four separate codebases for one product. We consolidated to one client-side codebase. Development costs dropped by roughly 60% and the founder could reason about the architecture himself.
An early-stage founder needed a CTO from day one, not a developer. I wrote the spec, picked the stack, and managed an external vendor on his behalf. The first prototype was live two months later, and the product is still on that stack today.
A Series B SaaS company lost its CTO and started to drift. Two weeks of focused work produced a one-year roadmap and an execution plan for server costs. The team delivered a 40% cost reduction without further input from me.
A pre-seed founder needed both a named CTO for investors and a working prototype. Both came from the same person. The company secured funding on the back of a coherent technical story and a working product, not slides.

The pattern across all of these is the same. The problem was not a lack of engineers. It was a lack of someone senior enough to see the whole system — technical, commercial, and regulatory — and make the right call.

That is what a fractional CTO does.

B2C / MobileB2C startup, Series A

Untangling a four-codebase mobile product

Three weeks of daily work, followed by a weekly one-hour check-in for several months.

Challenge

The founder had built the product with an external vendor and had been involved throughout, but was not technical and could not meaningfully assess the decisions being made. What the vendor delivered was four separate codebases: a Node.js backend, a native iOS app in Swift, a native Android app in Kotlin, and a React web frontend. Every feature change meant paying four engineering streams to build the same thing. Development was slow and expensive, and the cost structure was a real constraint on the company’s runway.

Approach

I reviewed the product architecture and the team’s actual delivery patterns. The backend was sound and stayed on Node.js. For the client side, React Native was the obvious choice. The backend was already JavaScript, which meant one full-stack developer could now cover what previously required separate iOS, Android, and web specialists. We consolidated iOS, Android, and the web frontend into a single React Native codebase. The client side ended up being maintained by a single fractional full-stack developer. From planning to execution the migration took three weeks.

Outcome

The migration was a real investment, but development costs afterwards dropped by roughly 60%. Feature delivery became fast and inexpensive instead of slow and expensive. The founder regained the ability to make product decisions without first weighing them against four parallel implementation costs, and the architecture was now simple enough that he could reason about it himself.

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B2C / Early stageEarly-stage B2C startup

Fractional CTO from day one for a vendor-built product

Three weeks of daily work through stack selection and team setup, followed by a weekly one-hour check-in through launch and beyond.

Challenge

The founder knew the domain and had a clear product idea, but no technical background of his own. He came to me looking to hire a developer. The product itself was not particularly complex; what made it interesting was the business logic and a lot of custom visual work on the client side.

Approach

Looking at the scope, hiring me as a developer did not make sense: it would be expensive for what he actually needed. Instead, I took on the Fractional CTO role: writing the technical specification, helping select an external vendor, and managing the build on his behalf.

We brought in a four-person vendor team with frontend, backend, mobile, and sysadmin roles. The mobile and sysadmin work was front-loaded into the initial setup and then handed off, leaving the frontend and backend developers as the steady-state team through the build.

For the stack we chose Spring Boot with PostgreSQL on the backend. On the client side we picked Flutter, which was the one deliberate exception in an otherwise conventional stack. Normally I would have gone with React, but the amount of custom animation work made Flutter the faster path to a working product. I planned the technical setup, including the release pipeline and testing approach, and handled code review in the early phase. Once the build was running, my involvement settled into a weekly check-in through launch and beyond.

Outcome

The first prototype was live two months from the start of the engagement. The product reached the market and is still in active development today on the same stack, without rewrites. The vendor team has since been replaced by an in-house team, which the original architecture supports without change.

B2B SaaS / FintechB2B SaaS in the financial sector, Series B

Stepping in after a CTO departure

Two weeks of focused work.

Challenge

The CTO had left and things had started to drift after the departure. The team was still delivering, but the engineering budget had stopped earning its keep. Investors were asking questions about how much the product was costing to run, and the CEO did not have a clear picture of what the engineers were actually working on. There was no shared twelve-month view to point to.

Approach

I started with the technical stack. Some of it was still useful, some of it had outlived its usefulness, and a couple of services were no longer being used at all. From there I moved to the cost picture. I did not have direct access to the invoices, so I worked through the spend with the CEO, service by service. The bigger line items were easy to spot. I then took those back to the team, and between us we worked out that some of the infrastructure was obsolete, and another part of it needed to be rewritten to use resources more efficiently. With the technical direction settled, I worked with the team to reorganise around clearer ownership, and built out a one-year delivery roadmap. As the team moved into the build phase, I helped them adopt AI-assisted development practices, with specs as the working unit rather than tickets.

Outcome

Monthly server costs came down by 40%, which the finance team noticed, and the team delivered the reduction without further input from me. I presented the one-year roadmap to leadership, then sat down with the CEO and the engineers together to walk through it, so both sides understood the business reasons behind the technical work for the year ahead. The roadmap turned into tickets in Jira, with a proper handover, and the team carried it from there. The CEO had a clear picture of what the engineers were working on, and could tell the investors that the company had a CTO in place, on an interim basis, who had reorganised things. The team also came out of the transition with a way of using AI coding tools in their daily work that kept them more productive and in control of the code, while shipping faster and at higher quality. The company avoided the slow erosion that usually follows a senior technical departure.

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Pre-seedPre-seed startup

Prototype to funded startup as the named CTO

Two months of building and technical leadership through the funding round, followed by regular check-ins over the following year.

Challenge

The founder had a product idea and needed two things at once: a credible technical story for investors (a specification and a named CTO behind it), and a working prototype to demonstrate the concept. Pre-seed founders often have to choose between these, because credible technical leadership is expensive and prototype work usually goes to a separate vendor. The result is documents and demos that don’t add up to the same product.

Approach

I came in as the fractional CTO, with the named role for investor conversations included. I produced the technical specification and added an architecture document on top of it. Once that material was in place, it became clear that a working prototype could be built directly from it, and I did that using Claude Code in a couple of weeks. After the funding round, I helped the founder assemble the engineering team and handed the product over to them, staying involved as a periodic technical reviewer to keep an eye on the codebase as the team grew.

Outcome

The founder secured the funding on the back of a coherent technical story and a working prototype, rather than slides and good intentions. The company is operating with its own team, and I stay close enough to catch issues before they become expensive. This is a pattern I have run with several pre-seed founders.

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