Your fractional CTO for the first 90 days
For funded, non-technical founders who need to ship, not to hire. You raised money. You have a product to build, engineers to hire, and technical decisions piling up that you can't evaluate. A full-time CTO costs $200k+ and takes six months to find. An agency will build whatever you ask for, including the wrong thing.
I do something different. For 90 days, I act as your CTO. Then I hand you the keys.
★ 5.0 on Google Backed by a senior studio team Ends on day 90, by design
Daniel Berigoi
13+ yrs full-stack · Runs Wingravity since 2017
What you get, day by day
Three phases, one terminus: a written handoff that makes you the owner of your own technical destiny.
- 01 Days 1–15
Foundation
Architecture decided and documented. Stack chosen with reasons written down, not vibes. Scope cut to what actually needs to exist for launch. Vendor and tooling decisions made.
- 02 Days 16–75
Build and hire
Your MVP shipped or in flight, built by my studio's senior team under my direct oversight. The build itself is scoped and quoted separately in week one, so you see both numbers before committing to either. In parallel, I run your first engineering hire: job spec, sourcing filter, technical interviews, offer. By day 90 you have an engineer signed or a live pipeline of vetted candidates.
- 03 Days 76–90
Handoff
A written decision log covering every technical choice made and why. A 6-month technical roadmap. A working relationship between your new engineer and the codebase. A final session where I walk your team through all of it.
The engagement ends on day 90. You get a CTO's full intensity with a deadline, and you are never dependent on me.
A company is never finished; the engagement is. Done means the handoff document is delivered, the decisions are on paper, and someone on your side owns what happens next.
A narrow offer, on purpose
This works because it fits a specific moment in a company's life. If that's not your moment, I'll tell you on the call.
Pre-seed to seed startups with funding in the bank
You raised money and now technical decisions are piling up faster than you can evaluate them. A full-time CTO costs $200k+ and takes six months to find.
Non-technical founders who need to ship, not to hire
You need someone to own the technical side completely: architecture, vendors, the build, the first engineering hire. Not a consultant who writes recommendations.
Technical founders who must stay on product and sales
You could do this yourself, but every hour you spend on infrastructure decisions is an hour not spent with customers and investors.
Companies looking for a permanent CTO
That's a different search. I can run it for you as part of the 90 days, but I'm not the hire.
Teams that already have strong technical leadership
If your technical decisions are getting made well, you don't need me. You might need my studio's delivery team, which is a different conversation.
Idea-stage founders without budget
Talk to me anyway. I'll point you somewhere useful, and it costs you a 30-minute call.
Fractional CTO, full-time hire, or dev agency?
Every funded founder weighs the same four options for technical leadership. Here's the honest comparison, including where the others win.
| What matters | Full-time CTO | Ongoing fractional CTO | Dev agency | ▸ 90-day CTO (this) |
|---|---|---|---|---|
| Cost | $200k+ a year, plus equity | €3–8k per month, open-ended | Project fees, no leadership | €15,000 flat for 90 days |
| Time to start | 3–6 months to find and close | Days to weeks | Weeks of sales cycle | Days |
| Owns technical decisions | Yes | Advises; you still decide | No, builds what you ask for | Yes, documented in a decision log |
| Builds the product | After hiring a team first | Rarely | Yes, whatever you ask for | Yes, senior studio team (quoted separately) |
| Runs your first engineering hire | Is the hire | Sometimes | No | Yes, included |
| How it ends | It doesn't; that's the point | Open-ended retainer | At delivery, code handed over | Day 90: written handoff, you own everything |
To be clear about where the others win: if you're at the stage where a permanent CTO makes sense, hire one, and I'll help you run that search. If you already have strong technical leadership and just need hands, a good agency is cheaper than a CTO. This engagement is for the 90 days before either of those is the right call.
One flat fee. No timesheet.
Most fractional CTO retainers are open-ended. This one is a number, a deadline, and a written list of deliverables. The deliverables are the contract.
- Architecture and every technical decision, documented
- Direct oversight of the MVP build, whoever builds it
- Your first engineering hire, run end to end
- The written handoff: decision log, 6-month roadmap
- A CTO's full attention with a hard deadline
What it deliberately doesn't cover: the MVP build itself. If my studio builds it, that's scoped and quoted as a separate fixed-scope project in week one, so you see both numbers before committing to either. If your own engineers or another vendor build, my job stays the same. A CTO who profits from every line of code his team writes has a conflict of interest; separating the two fees removes it.
One-week technical audit
A trial run. I review your plans, codebase, or vendor quotes and give you a written read on where you actually stand. If we continue into the 90 days, the full amount is credited toward the fee.
Useful even if we stop there: you walk away with an independent second opinion you can hand to your investors.
A CTO who comes with a delivery team
The difference between me and a solo fractional CTO: architecture decisions get made and then get built, by the same people, under one roof.
I'm Daniel Berigoi. I've spent 13+ years as a full-stack engineer, and since 2017 I've run Wingravity, a product development studio serving healthcare, academic publishing, and travel clients across the EU and US, including work for the University of Cambridge. I've been the technical decision-maker on products from first commit to production the whole way.
Most fractional CTOs hand you a slide deck and wish you luck with the vendors. My decisions come with a senior team that has shipped healthcare platforms like Doc24 and AI products like SmartDecision AI into production. When I say an architecture will work, it's because the people sitting next to me have built it before.
Three ways it usually ends
All three are fine. The point of the deadline is that you choose, from a position of strength, instead of drifting into permanent dependency on an outside consultant.
Your engineer takes over
The handoff doc exists so this works. Your new hire owns the codebase, the roadmap tells them where to go, and the decision log tells them why everything is the way it is. Most common outcome.
Wingravity keeps building
If there's a phase two, my studio quotes it as a normal fixed-scope project. Same team that built phase one, no re-onboarding, no knowledge transfer tax.
Light advisory
A few hours a month for architecture reviews and hiring input, if you want a safety net. Small, defined, and cancelable any time.
What founders ask before saying yes
Short, honest answers. If yours isn't here, book the call and I'll answer it directly.
What is a fractional CTO, and how is this different?
// Answer
A fractional CTO, sometimes called a part-time or interim CTO, is an experienced technology leader who owns a company's technical strategy without being a full-time hire, usually on a monthly retainer. This engagement is different in one way: it ends. You get full CTO authority for 90 days, a written handoff, and a delivery team behind every decision, instead of an open-ended advisory relationship.
How much does a fractional CTO cost?
// Answer
Ongoing fractional CTOs typically charge €3,000 to €8,000 per month, and the retainer has no defined end. This engagement is €15,000 flat for the full 90 days, paid in three monthly installments, with the deliverables written into the contract: architecture documented, MVP oversight, your first engineering hire, and the handoff doc. No hourly tracking, no meter running.
Why 90 days and not ongoing?
// Answer
Because open-ended fractional CTOs create dependency. My job is to make the decisions, ship the foundation, and make myself unnecessary. You should own your technical destiny by day 91. The deadline is also what makes the intensity possible: you get a CTO's full attention because it has an end date.
Does the €15,000 include building the MVP?
// Answer
No, and that's deliberate. The fee buys my judgment, decisions, hiring, and oversight. The build itself is a separate line: if my studio does it, we scope and quote it as a fixed-scope project in week one, and you see both numbers before committing to either. You're equally free to have your own engineers or another vendor build; my job stays the same. Anyone who tells you €15k covers a CTO and a senior team building your MVP for three months is hiding the real cost somewhere.
What if the MVP isn't done at day 90?
// Answer
The 90-day scope is set in week one, together, and it's set conservatively. If we scope it right, it ships. If you expand scope mid-way, we re-plan together and the extra work is quoted separately. Either way, the handoff still happens on day 90: done means the document is delivered, not that nothing is left to improve.
Do I need a technical cofounder instead?
// Answer
A technical cofounder costs 10 to 50 percent of your company and, like a full-time CTO, takes months to find, if you find one at all. For most funded startups the actual need is 90 days of good decisions plus a strong first engineering hire, and that's exactly what this engagement delivers. You keep the equity. If a cofounder-level partner later makes sense, you'll be choosing one from a working product instead of a pitch deck.
Do you write code yourself?
// Answer
When it's the fastest path, yes. Mostly I decide, review, and unblock while the team builds. You're paying for judgment, not keystrokes.
Can we start with something smaller?
// Answer
Yes. A one-week technical audit (€2,500) works as a trial: I review your plans, codebase, or vendor quotes and give you a written read on where you actually stand. If we continue into the 90 days, it's credited toward the fee.
A 30-minute call, nothing more
You tell me where you are, I tell you honestly whether this fits. If it doesn't, I'll tell you that too.
Talk to Daniel directly
No sales pitch, no discovery-call theater. You'll leave knowing whether the 90 days fit, and what I'd do first if they do.
Tell me where your startup is
Share what you're building, what you've raised, and what's keeping you up at night. I reply within one business day.