FRACTIONAL & INTERIM CTO · CTO AS A SERVICE

Fractional CTO in Spain: the technical decisions you can't afford to get wrong, made by a working CTO.

A fractional CTO is a CTO who works for your company a fraction of the month and owns the architecture, the engineering hires, a due diligence or the AI in the product, without the cost or commitment of a full-time hire. Billed by the hour.

Tell a CTO →How the seat works ↓

WHAT IT IS

What isa fractional CTO?

A fractional CTO is a working chief technology officer who takes the seat in your company for a fraction of the month, from two days a month to half-time, and owns the technical decisions you cannot undo: the architecture, the first engineering hires, the due diligence with investors and which AI goes into the product. Not a consultant who recommends and not a senior developer who executes: a CTO's decision rights, without the salary, the equity or the commitment of a full-time one.

An interim CTO is the same seat at a larger fraction and for a bounded time: it covers the role at half-time or more while you search for the permanent one, and hands over when they arrive.

How do you hire a fractional CTO in Spain?

Four steps, from the first message to the CTO in the room. No hiring process, no probation period, no six-month search: a services contract, a monthly invoice and 30 days' notice.

Write the decision, not the job description.
Tell us what is in front of you: the architecture that has to hold for two years, the hire nobody can interview, the round, the AI feature. A CTO reads it and replies within 24 hours.
A diagnostic conversation with the CTO who would take the seat.
One hour, with the people who decide. It ends with which fraction of the month your decisions need (advisory, fractional or interim) or with the honest answer that you do not need the seat yet.
A one-page proposal: the fraction, what the CTO owns, and the terms.
Billed by the hour, monthly, with a retainer and 30 days' notice. No recruitment fee, no equity, no exclusivity. You know the number before you sign.
Start within days, inside your tools.
The CTO joins your repositories, your tracker and your weekly, in English or Spanish and on European hours. The first written verdict (architecture, hiring bar or AI roadmap) lands in the first month; the fraction moves up or down as the company changes.

WHEN

Signs you needa CTO now

Your roadmap is decided by whoever shouts loudest, not by a software architecture or a long term strategy.
You are about to hire software engineers and nobody can interview them.
Investors ask technical due-diligence questions you cannot answer.
An agency built the product, nobody owns it, and you want engineering in-house.
You need to put AI in the product and you do not know what is real and what is a demo.
Your CTO left, or is on leave, and the roadmap cannot wait for a six-month search.

A fractional CTO leading a planning session with the team

WHAT

An expert helpingyou decide

Architecture guardrails

The data model your next two years will sit on, where the service boundaries fall, and the build-versus-buy line on auth, payments, search and the twelve other things you could write yourself and shouldn't. The guardrails that prevent the expensive rewrite.

The first engineering hires

Who interviews them, where the hiring bar sits, and which senior you let set the standard everyone else codes to. Our own bar admits 3 % of applicants; holding one is a decision, not a process.

Roadmap arbitration

Sales needs the integration, marketing the dashboard, the CEO the mobile app, all of it yesterday. Someone with the decision rights says what is feasible this quarter, in what order, and which one should never be built. Fewer stalled debates, more momentum.

LLM feature or rule

Which model, at which layer, under what fallback, with evals and a cost ceiling, and which parts of the workflow stay human. A demo costs nothing to get wrong; a feature billing tokens on production traffic does.

The technical narrative for investors

Due diligence in both directions: the one investors run on you before a term sheet, and the one you run on a vendor or on the codebase an agency left behind. And a technical narrative you can defend in the room.

WHO

Who sits in the seat

A senior engineer reviewing code with a younger colleague at a laptop

Working CTOs and principal senior engineers: executive-level judgement before you can recruit the full-time role.

Each seat is matched to the decisions in front of you: the architecture, the hiring loop, the room with the investors, the migration nobody wants to own. Conectia's own CTO takes some of them; senior CTOs from the bench take the rest.

Behind the seat there is a bench of experienced C-level senior engineers, a team one conversation away when the company is at stake.

PROOF

Case studies

The core of an identity protocol, shipped by an embedded squad with a CTO at the front.

mintid: a squad of three engineers plus a CTO, embedded since March 2026, building the protocol core and the verifier SDKs.

A first engagement renewed at double the scope
Zero bugs escaped to production
Embedded in the client's repositories and trackers, not hosted

Read the case study →

From idea to production in 90 days, with four engineers and a fractional CTO.

Ealyx, Barcelona: circularity software for e-commerce. Since May 2024 a Conectia team has carried the product from the idea to production, as one team with the founders.

Idea to production in 90 days
Four engineers plus a fractional CTO, one team
An ongoing relationship since May 2024

See all cases →

A legaltech founder with no technical co-founder, in production with paying users.

Bonus Iuri: contract risk analysis backed by Spanish legislation. The founder brought the domain; the seat brought the architecture, the model choices and the team.

MVP in production in 42 days
Nine contract types analysed with article-level citations
No CTO hired, no round raised first

Read the case study →

FORMATS

From hours to days to weeks

ADVISORY · 2 DAYS A MONTH

A second opinion on every irreversible decision

Architecture reviews, the hiring interviews, board and investor preparation. The decision set fits in two days a month; the calendar does not need to be full for the decisions to be good.

Move up when: the team crosses five engineers and somebody has to hold the quality bar every week, not every fortnight.

FRACTIONAL · 1 DAY A WEEK

Owns the technical roadmap

Runs the operating cadence: a weekly sync with the founders, the engineering rituals, the pull requests that matter, and unblocks the mid-level engineers.

Move up when: you are shipping AI to real users and the evals, cost limits and observability need a weekly review by someone who has done it.

INTERIM · HALF-TIME

Acts as your CTO until you hire one

To the team, the vendors and the investors, with code in the loop: the architecture they defend is the one they wrote.

Move up when: a funding round, a diligence window or a CTO vacancy puts the seat in the room for six weeks, sometimes a quarter.

Billed by the hour, monthly, with 30-day notice and a retainer.

Two people planning a four-quarter roadmap with sticky notes on a glass wall

WHAT THEY SAY

Founders and CEOswho bought commitment

Working with Conectia has been a very positive experience. They have a solid, committed technical team with a great ability to adapt to the needs of the project.
I would especially highlight the quality of their deliveries, their respect for deadlines and communication that is always clear, approachable and solution-oriented. They also integrated very naturally into our team, making collaboration easy from day one.
Without a doubt, a trusted partner I would recommend.

Aaron has a great ability to structure complex problems and turn them into clear solutions. He always finds a way to move things forward. He thinks strategically and long-term, rather than reaching for quick fixes. He has a great sense of humour and a very positive attitude that adds real value to the team.

Working with Fernando was very easy: from his warm, positive character to his problem-solving and technical ability. A great teammate you could always count on.

It is a pleasure to recommend Conectia's services as a development company.
Their service offering stands out for being comprehensive, covering every phase of the process with technical rigour, adaptability and a genuinely client-oriented approach. Their team combines professionalism and warmth — two qualities that don't always go together and that, in this case, translate into a truly positive collaboration.
For any organisation or professional looking for a trustworthy technology partner, Conectia is an option to consider with complete confidence.

Conectia gave us a highly technical working team with outstanding project management within a week. Our project is a complex blockchain protocol system for Know Your Agent identity in the agentic era, so not every software developer can take on this challenge. Conectia has allowed me to focus on White Paper writing, high level architectural decisions and stakeholder management while they handle EVERYTHING on engineering and I know I do not need to worry. The deliverables will come on time and in excellence beyond expectations. No bugs, no delayed deploys, no surprises. Just solid planning and execution.

TALK TO A CTO

Tell a CTO. You get a reply within 24 hours.

Message us on WhatsApp

Write the decision in front of you: the architecture, the hire, the round, the AI feature. A CTO reads it and replies with which fraction of the month it needs, or with the honest answer that it does not need the seat.

The reply carries the fraction and the number, within one business day.

Need a CTO for your project?

Executive-level technical judgement without a full-time hire.