Most founders have never hired a CTO before — fractional or otherwise — so the assessment call tends to default to gut feel. These twenty questions replace gut feel with evidence. For each one: why it matters, and what a good answer sounds like.
Quick answer
The questions that matter most when hiring a fractional CTO: what they’ve built and operated at your stage, a measurable outcome from a past engagement, how many clients they run concurrently, whether they’ll review code and architecture themselves or delegate it, how they handle the handover when the engagement ends, and their exact commercial terms — hours, invoicing, IP assignment. Weak answers on track record and availability are the two most reliable predictors of a failed engagement.
Track record (questions 1–5)
1. What have you built and operated at our stage?
Stage fit beats brand names. Someone who has scaled a 10-person platform team knows problems a big-company CTO has never had. Good answer: a specific business at a similar size, and what changed while they were there.
2. Tell me about one measurable outcome from a past engagement.
Anyone can describe activity; operators describe outcomes. Good answer includes a number — release cadence, uptime, hiring, cost, a funding round passed cleanly.
3. When did you last write or review production code?
You’re not hiring them to code, but a CTO who can no longer read a pull request can’t challenge your developers or your agency. Good answer: recently, and unprompted specifics about the stack.
4. Have you worked in our industry’s regulatory environment?
Fintech (ASIC, PCI DSS), health (privacy, sensitive data), government (IRAP, AusTender) each carry obligations a generalist can miss. Good answer names the frameworks and what they did about them, not just the acronyms.
5. Can I speak to two past clients?
References should be offered without friction. Ask the referees one thing: what changed measurably while this person was engaged?
Engagement and availability (questions 6–10)
6. How many clients do you run at once?
Fractional works because attention is scoped, not infinite. Good answer is a specific, honest number with an explanation of how hours are protected. Evasive answers here predict missed meetings later.
7. Who exactly does the work — you, or a team behind you?
Some providers sell a senior face and deliver juniors. Either model can work, but you must know what you’re buying. Good answer: complete transparency about who touches what.
8. What happens when we need you urgently — an outage, a board crisis, a security incident?
Good answer distinguishes scheduled hours from genuine emergencies and tells you honestly what’s included, what costs more, and how fast they can be reached.
9. What does your typical month with a client look like?
You’re listening for structure: a standing leadership call, review cadence, written reporting — not “whenever you need me”, which sounds generous and delivers nothing.
10. How do engagements with you usually end?
The best fractional CTOs work toward their own redundancy: a permanent hire recruited and onboarded, a team levelled up, documentation that survives them. Wariness about this question is a red flag.
Technical judgement (questions 11–15)
11. Look at our stack for ten minutes and tell us what you’d examine first.
You’re not testing whether they flatter your choices — you’re testing whether they form independent views quickly and explain them clearly to a non-technical founder.
12. When would you recommend a rebuild?
Trick question. The correct instinct is almost never in the first conversation — rebuilds are occasionally right and usually a trap. Good answer: incremental paths first, rebuild only with evidence.
13. How do you evaluate whether our developers or agency are doing good work?
Good answer covers artefacts (code review, deployment pipeline, incident history) rather than vibes, and includes talking to the developers themselves.
14. What’s your approach to security for a business our size?
Good answer is proportionate — Essential Eight-style basics, access control and backup discipline before expensive tooling — and mentions what auditors or acquirers will actually check.
15. How do you make build-vs-buy decisions?
Good answer: a bias toward buying commodity capability and building only what differentiates the business, with a real example either way.
Commercial and governance (questions 16–20)
16. What are your exact terms — hours, invoicing, notice?
Professional providers answer instantly because it’s written down. As a benchmark: our plans are published openly (A$1,000–A$22,000/month for 2–40 hours), pre-paid monthly, tax-invoiced and settled by EFT. Compare market rates in our 2026 cost guide.
17. Who owns the IP you create for us?
The only acceptable answer: your company, assigned in writing. Anything else, walk away.
18. Do you carry professional indemnity insurance and invoice with an ABN?
Basic hygiene for anyone advising at executive level in Australia — and something your acquirer’s lawyers will eventually ask about.
19. What conflicts of interest should we know about?
Good answer discloses other clients in adjacent spaces and any vendor relationships or referral fees. A CTO who earns commission on the platforms they recommend is not giving you independent advice.
20. How will we know after 90 days whether this is working?
The best candidates propose their own success criteria before you ask. We’ve published what a fractional CTO should deliver in the first 90 days — use it as the baseline.
Scoring the answers
Don’t average across all twenty — weight them. Track record (1–5) and availability (6–10) are the strongest predictors of engagement success; a candidate who is impressive technically but vague about concurrent clients will disappoint you. Two or more evasive answers in one section is a pattern, not bad luck.
Frequently asked questions
How many of these questions should I actually ask?
Pick the ten that map to your situation — five from track record and availability, five from wherever your risk is (technical judgement for product businesses, governance if you’re heading to funding or acquisition).
Should a non-technical founder run this assessment alone?
You can — every question here is answerable in plain English, and how clearly they explain is itself the test. For deeper technical validation, an independent review of the candidate’s plan after 30 days works well.
What’s the single biggest red flag?
A recommendation to rebuild your platform in the first conversation, before they understand the business. It’s the most expensive advice in software and it’s almost always wrong on day one.
Want to put these questions to someone senior? See our published pricing, read the complete guide to hiring a fractional CTO in Australia, or book a discovery call.