What a fractional CTO does (and when you don’t need one)

Outside Spain the term "fractional CTO" is fairly settled. Here, when you say it in a meeting, the usual reaction is to assume it means a consultancy that delivers a report, or a senior developer with a high rate. It is neither.

The short definition

A technical director who works for your company a few days a month, continuously, with responsibility for decisions. The difference from consulting is continuity and accountability; the difference from a developer is that the work is deciding, not executing.

What they actually do on those days

• Translate business objectives into a technical plan with cost and risk, in a format you can take to a board.
• Evaluate vendor proposals and negotiate scope in the vocabulary of the other side of the table.
• Make — and sign off on — architecture decisions, including the decision not to build.
• Define technical roles, take part in interviews and set up the team’s engineering practice.
• Quantify technical debt so it can be prioritised like any other investment, rather than mentioned in every meeting without numbers.

When it makes sense

When technology is already a meaningful part of the budget and the operation, but the volume does not justify a full-time CTO. In practice, companies of ten to a hundred and fifty people, or startups with a product in market and a small engineering team.

There is also one very clear case: when a single trusted developer has become a single point of failure, and nobody in the company can evaluate their work or replace them if they leave.

When you do not need one

• If what is missing is hands, not decisions. If the plan is clear and only needs executing, what you need is development capacity, and it is cheaper.
• If you already have an internal technical lead with judgement. In that case a one-off second opinion may help, but not a continuing engagement.
• If technology is not critical to the business. A company whose operations do not depend on software does not need technical leadership; it needs a good vendor and a reasonable contract.