Fractional CTO for startups: what you need at each stage
A fractional CTO for startups gives an early company senior technical judgement for a day or two a week, at the moments when a wrong call is expensive: choosing the stack, making the first engineering hires, getting ready for due diligence. What you need from that person changes a lot between pre-seed and Series A.
I’ve co-founded a company and sold it, been CTO through an acquisition and built several products from zero. Here’s what I think matters at each stage, and when you don’t need someone like me at all.
Pre-seed: decide what not to build
At pre-seed, the technical risk is mostly wasted time. The useful work is:
- Build vs buy for everything that isn’t your core. Auth, payments, email, search and admin should almost always be bought or taken off the shelf. See build vs buy software.
- Choosing a stack you can hire for. A boring framework and PostgreSQL. No microservices, no Kubernetes.
- Deciding who builds the first version – a founder, a freelancer, an agency – and setting it up so the company owns the code and accounts.
- Scoping the first release down to the one workflow that proves demand.
At this stage you might need only a few hours of a technical advisor’s time a month. A full fractional CTO arrangement is often overkill, and I’ll tell you so.
Seed: the first engineering team
Seed is where most startups first need real technical leadership, because the work shifts from building to building a team that builds:
- The first two to five engineering hires. Writing job specs that attract the right people, a practical interview loop, and deciding whether your first hire is a senior generalist or a future lead. (Usually a senior generalist.)
- Just enough process. Pull request reviews, a staging environment, deploys that happen daily and boringly, error tracking. Not story points and sprint ceremonies for three people.
- Security basics before your first enterprise customer asks. SSO for your own tools, secrets out of the repo, least-privilege cloud access, backups that restore.
- Investor questions. Being able to explain in plain language how the product is built, what the technical risks are and what the money will be spent on.
Series A: preparing for scale and scrutiny
- Due diligence readiness. Some Series A investors commission a technical review. Know what they’ll find. The technical due diligence checklist is a fair preview.
- Hiring the permanent technical leader. A full-time CTO or VP Engineering, and a clear handover from the fractional arrangement.
- The first architecture limits. The database, the background jobs, the one feature built in a hurry that now carries half the revenue.
- Delivery as the team doubles. What worked at five engineers starts to break at twelve. Team boundaries, ownership and on-call need deliberate design.
Past Series A, the work looks more like the growth-stage SaaS engagements: less founding, more scaling.
How it fits a startup budget and pace
Startups change direction often, so my engagements are built for it. We start with a two-week sprint where I ship something real and give you a written view of the technical risks. If it’s working, we agree a fixed number of days per week. If your needs shrink – the first senior hire lands, the technical risk drops – the days shrink too, or we stop. No notice period, no exit clause.
The goal at every stage is to make myself unnecessary: leave decisions written down and hand over to someone on your team who can own them. If you’re comparing this against a full-time hire, see fractional vs full-time CTO.
Technical advisor or fractional CTO?
A startup technical advisor is typically a few hours a month: a sounding board for founders, maybe a board seat or advisory equity. A fractional CTO takes ownership – they’re accountable for the technical side of the company for the days they work, and they make decisions rather than suggestions.
If your founding team includes a capable technical founder who mainly needs someone experienced to talk to, an advisor is the better fit. If nobody owns the technical decisions, or the technical founder is drowning, you need ownership. If you have no technical founder at all, read technical cofounder alternatives first.
Questions
When does a startup need a fractional CTO?
Usually around seed, when the company moves from building a first version to building an engineering team. Before that, occasional advice is often enough. Earlier is justified if nobody on the founding team can judge technical work and significant money is about to be spent on development.
What does startup technology consulting include?
It typically covers stack and architecture choices, build vs buy decisions, scoping the first product, hiring the first engineers, setting up delivery practices and security basics, and preparing for investor due diligence. With me it also includes hands-on work in the codebase.
Should a fractional CTO get equity?
It depends on the arrangement and what both sides want. Advisory equity is common for light-touch advisors. For a paid fractional role, cash is more typical. Whatever you agree, keep it separate from any future full-time CTO’s package, which will need room.
Can a fractional CTO help us hire a full-time CTO?
Yes, and it’s one of the most useful things they do. After working in your codebase and team, a fractional CTO can write a realistic job spec, run the technical interviews and plan the handover, which makes the permanent hire far more likely to succeed.
Early-stage and unsure what technical help you need?
Tell me your stage and what’s worrying you. If a two-week sprint makes sense we’ll plan one; if a few hours of advice will do, I’ll say so.
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