What a fractional CTO is actually for
Crescentic provides fractional CTO services for companies that need a senior technical voice without a full-time executive hire: architecture and roadmap, build-versus-buy, AI strategy, hiring, security audits and technical due diligence. We stay long enough to be there when the decisions land. This page is for founders and boards making technical decisions that will echo for years, without a senior technical person in the room.
Sometimes you do not need hands on keyboards. You need someone who has made this decision before, sitting at the table when it gets made, and still around when the consequence arrives.
Most companies at this stage have a small number of choices a year that matter enormously — the architecture, the platform bet, the first engineering hire, whether to build the thing or buy it — and a large number of weeks in between where an executive would be underused. That gap is what the arrangement is for.
- Architecture and technology decisions, with the reasoning written down.
- Build versus buy, evaluated on total cost rather than licence price.
- AI strategy — what to build, what to buy, and what to wait on this year.
- Hiring: the role, the interview, and the assessment you cannot make yourself.
- Vendor evaluation, including the technical claims in the contract.
- Board and investor conversations, as the technical voice in the room.
- Security audits, certification, and technical due diligence.
An advisor gives an opinion and leaves. This is accountability for the decision.
The value is not the recommendation — it is being there a year later when the consequence shows up, which is the only honest test of whether the advice was right.
What does this look like on a real engagement?
The clearest example is a compliance and global-mobility platform used to set up entities, move staff and stay legal across more than 170 countries. We build and maintain its web application and own the AWS infrastructure it runs on — and the leadership work sits on top of that rather than beside it.
That combination is the argument for this service line. The people answering the auditor’s questions are the people who moved that platform from hand-managed Docker Compose hosts to Terraform-defined AWS across four environments. There is no translation layer between the technical leadership and the technical work.
When do you need one, and when do you not?
| Advisor | Fractional CTO | Full-time CTO | |
|---|---|---|---|
| Owns the decision | No — offers a view | Yes | Yes |
| Present for the consequence | Rarely | Yes | Yes |
| Cost | Low | A fraction of a salary | Salary plus equity |
| Right when | You need one conversation | Decisions are big but not daily | Technical leadership is the daily job |
| Can execute what they recommend | No | Yes — our engineers | Yes — their team |
We will tell you when the answer is a full-time hire. If technical leadership has become a daily job at your company, a fraction of a person is the wrong shape and stretching the arrangement to fit serves nobody. In that case the useful version of this engagement is helping you hire the person and handing over cleanly.
How the engagement runs
- 01
Start with what is actually in front of you
A funding round, an audit, a platform decision, a hire. Something concrete and dated, not a general retainer for availability.
- 02
Read the system before advising on it
The codebase, the infrastructure, the release process and the team. Advice given without this is worth what it costs to produce.
- 03
Be in the room where it is decided
Board conversations, investor calls, vendor negotiations, interview panels. The technical voice has to be present when the decision happens, not consulted afterwards.
- 04
Stay for the consequence
Decisions of this kind reveal themselves over quarters. We are still there when they do — and when something needs building, our engineers build it.
Technical due diligence, from either side
If you are raising or being acquired, we prepare and defend the technical story — and fix what will not survive contact with a competent reviewer before the reviewer finds it.
If you are investing or acquiring, we assess the target: what is really under the hood, what the architecture diagram leaves out, which risks are real and which are cosmetic, and what the first year of owning it will actually cost. Written plainly, for people who have to make a decision with it.
01.What is a fractional CTO?
A senior technical leader who works with you part-time and carries real responsibility for technical decisions — architecture, hiring, vendors, roadmap, risk — without being a full-time executive hire. The difference from an advisor is accountability: a fractional CTO owns the decision and lives with the consequence, rather than offering an opinion and leaving.
02.When should a company hire a fractional CTO instead of a full-time one?
When the technical decisions are consequential but not yet continuous. A pre-Series-A company usually has a handful of choices a year that will echo for a decade, and no need for an executive in every meeting in between. Also when you are hiring a permanent CTO and need someone credible in the room until they arrive, or when the board needs an independent technical read it can trust.
03.What does a fractional CTO actually do day to day?
Architecture and technology decisions and the reasoning behind them. Build-versus-buy calls. Evaluating vendors and reviewing their contracts for the technical claims. Hiring — writing the role, sitting on interviews, assessing candidates you cannot assess yourself. AI strategy, meaning what to build, what to buy, and what to leave alone this year. Sitting in board and investor conversations as the technical voice. Supporting audits and diligence when they arrive.
04.Can you support an ISO 27001 audit or a security review?
Yes, and we do this on an ongoing basis. We support one client's annual ISO 27001 audit — the recurring evidence, the infrastructure questions, and the answers that need to hold up in enterprise procurement and security review. That work is easier when the same people also run the infrastructure being audited, which is generally our situation.
05.Do you do technical due diligence for investors or acquirers?
Both sides of it. We have supported a client through the technical diligence that accompanied their fundraising — being the technical voice answering an investor's engineers. We also assess targets for people considering an investment or acquisition: what is really under the hood, what the stated architecture leaves out, and which risks are genuine versus cosmetic.
06.How is this different from hiring a consultancy for a strategy engagement?
A strategy engagement ends in a document. This does not end. The point of the arrangement is continuity — being present for the decision, then still being there a year later when the consequence arrives, which is the only way to know whether the advice was any good. It also means we can hand work to our own engineers when a recommendation needs building, rather than passing you to a procurement process.
The rest of what we do
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