You've decided you need a fractional CTO. You've found some candidates. Now comes the hard part: figuring out which one is right for your situation.
The title "fractional CTO" covers a wide range of people with very different backgrounds, skills, and approaches. Some will transform your technology situation. Others will bill hours without delivering value.
Here are the questions that help you tell the difference.
Experience Questions
"What types of businesses have you worked with?"
You want someone who's seen your type of problem before.
A fractional CTO who's spent their career in enterprise software might struggle with a scrappy startup. Someone focused on B2C e-commerce might not understand B2B manufacturing workflows.
Look for:
- Experience in your industry or adjacent industries
- Experience at your company size or similar
- Experience with your type of technology challenges
Red flag: Vague answers that don't demonstrate relevant experience.
"Tell me about a fractional engagement that went well. What made it work?"
This reveals what they think success looks like—and whether it matches your expectations.
Listen for:
- Concrete outcomes, not just activities
- Understanding of business impact, not just technical metrics
- Recognition of the client's role in success
- Realistic timeframes for results
Red flag: All credit goes to them. No mention of collaboration or client contribution.
"Tell me about an engagement that didn't go well. What went wrong?"
Everyone has failures. What matters is whether they learned from them.
Listen for:
- Honest acknowledgment of their role in the failure
- Specific lessons learned
- How they'd approach it differently now
- Willingness to discuss uncomfortable topics
Red flag: Blame-shifting. "The client didn't follow my advice." Inability to identify any failures.
"What's the biggest technology mistake you've helped a client avoid?"
This shows pattern recognition—the ability to see problems coming before they become expensive.
Good answers describe specific situations:
- The vendor they steered away from (and why)
- The architecture decision they changed (and what would have happened otherwise)
- The project they recommended killing (and how that saved money)
Red flag: Generic answers that could apply to anyone. No specific examples.
Technical Questions
"How do you stay current with technology changes?"
Technology evolves quickly. Someone relying on knowledge from five years ago will give outdated advice.
Listen for:
- Active learning habits (reading, courses, experimentation)
- Engagement with the technology community
- Intellectual curiosity about new approaches
- Healthy scepticism about hype
Red flag: "I've been doing this for 20 years, I know what works." Dismissiveness about new technologies.
"What's your approach to build vs buy decisions?"
This reveals their biases—and whether those biases fit your situation.
Listen for:
- Recognition that the answer depends on context
- Specific factors they consider
- Examples of recommending both building and buying
- Awareness of the real costs of each approach
Red flag: Strong bias in either direction without acknowledging trade-offs.
"How do you evaluate technical debt?"
Technical debt is inevitable. Managing it is a core CTO skill.
Listen for:
- A framework for assessing debt levels
- Understanding of when debt is acceptable vs. problematic
- Ability to translate technical debt into business impact
- Pragmatic approaches to paying it down
Red flag: Either "technical debt is always bad" (idealistic) or no systematic approach (negligent).
"What questions would you ask to assess our current technology situation?"
This shows their diagnostic approach—how they'd actually understand your environment.
Listen for:
- Questions about business context, not just technology
- Interest in team dynamics and history
- Focus on outcomes and constraints
- A systematic approach to assessment
Red flag: Jumping to solutions without understanding the problem. Only asking about technology, not business.
Working Style Questions
"How do you typically structure a fractional engagement?"
Understanding their default approach helps you assess fit—and negotiate appropriate arrangements.
Ask about:
- Typical time commitment (hours/days per week)
- Communication rhythm and channels
- How they handle urgent issues
- How engagements evolve over time
Red flag: One-size-fits-all approach that can't adapt to your needs.
"How do you handle disagreements with clients?"
Healthy relationships include disagreement. How they navigate it matters.
Listen for:
- Willingness to express unpopular opinions
- Respect for client decision-making authority
- Ability to disagree without damaging relationships
- Recognition that they might sometimes be wrong
Red flag: Either "I always defer to the client" (weak) or "I'm usually right so they should listen" (arrogant).
"How do you work with existing development teams?"
If you have developers, the fractional CTO needs to work alongside them.
Listen for:
- Respect for existing team members
- Focus on enablement vs. replacement
- Approach to mentorship and skill development
- Strategies for building trust
Red flag: Condescension toward existing teams. Approach of "I'll tell them what to do."
"What does a typical week look like in an engagement like ours?"
Get concrete about what you're actually buying.
Ask about:
- What activities occupy their time
- How they split between strategic and tactical work
- How they stay connected between formal meetings
- What outputs and deliverables to expect
Red flag: Vague answers. Inability to describe concrete activities.
Fit Questions
"What kinds of clients do you work best with?"
Self-awareness about fit helps both parties.
Listen for:
- Honest assessment of their strengths and preferences
- Types of situations where they've been most effective
- Characteristics of successful client relationships
- Willingness to acknowledge poor fit situations
Red flag: "I work well with everyone." Lack of self-awareness.
"What would make you recommend we don't work together?"
A confident fractional CTO knows when they're not the right fit.
Listen for:
- Specific situations where they'd decline
- Priority on finding the right fit over closing the deal
- Honesty about their limitations
- Suggestions for alternatives if they're not right
Red flag: Eagerness to take any engagement regardless of fit.
"What do you expect from us to make this engagement successful?"
Partnership goes both ways. Understanding their expectations helps you assess feasibility.
Listen for:
- Clear requirements for access and information
- Communication expectations
- Level of executive commitment needed
- Time commitment from your team
Red flag: No expectations. "I can work with anything." (This usually means problems later.)
Value Questions
"How do you measure success in a fractional engagement?"
Alignment on success metrics prevents disappointment.
Listen for:
- Connection to business outcomes, not just technical metrics
- Concrete, measurable criteria
- Realistic timeframes for seeing results
- Willingness to be held accountable
Red flag: Vague success criteria. "Things will be better." Inability to define measurable outcomes.
"Can you provide references from similar engagements?"
References are essential. Don't skip this step.
Ask references:
- What was the situation before they engaged?
- What did the fractional CTO actually do?
- What were the measurable outcomes?
- How did they handle challenges?
- Would you hire them again?
Red flag: No references available. References that don't match claimed experience.
"What happens if this doesn't work out?"
Understand the exit strategy before you enter.
Listen for:
- Clear terms for ending the engagement
- Knowledge transfer expectations
- Reasonable notice periods
- Professionalism about transitions
Red flag: Lock-in structures that make it hard to exit. Defensiveness about the question.
Practical Questions
"What's your availability?"
Fractional means part-time. Understand what that means specifically.
Ask about:
- Hours per week/month
- Response time for urgent issues
- Scheduling constraints
- Other clients and potential conflicts
Red flag: Over-commitment. Taking on more clients than they can serve well.
"How do you handle confidentiality?"
You'll be sharing sensitive information. Understand their approach.
Listen for:
- Standard confidentiality practices
- How they handle working with competitors
- What information they share between clients
- Willingness to sign NDAs
Red flag: Casualness about confidentiality. Stories that reveal too much about other clients.
"What's your fee structure?"
Understand what you're paying for.
Common models:
- Retainer (fixed monthly fee for defined scope)
- Hourly (pay for time used)
- Project-based (fixed fee for specific deliverables)
- Hybrid (retainer plus project fees)
Ask about:
- What's included vs. extra
- How scope changes are handled
- Payment terms
- Minimum commitment periods
Red flag: Unclear pricing. Hidden fees. Reluctance to discuss money directly.
The Interview Process
Beyond specific questions, pay attention to how the conversation goes.
Do they ask good questions? A fractional CTO who doesn't ask about your business before proposing solutions is a red flag.
Do they listen? Or are they waiting for their turn to talk?
Do they explain clearly? Technical expertise is useless if they can't communicate it to non-technical stakeholders.
Do they admit uncertainty? Nobody knows everything. Pretending otherwise is dangerous.
Do you like them? You'll be working closely with this person. Interpersonal fit matters.
Making the Decision
After interviews, compare candidates against what matters for your situation:
- Relevant experience: Have they solved similar problems?
- Technical capability: Can they handle your challenges?
- Communication: Will they work well with your team?
- Cultural fit: Do they match your organisation's style?
- Availability: Can they give you enough time?
- Value alignment: Do they measure success the way you do?
Don't just pick the most impressive resume. Pick the best fit for your specific needs.
Trust Your Instincts
If something feels off, pay attention. The best fractional CTOs are straightforward, confident without arrogance, and genuinely interested in your success.
If you're getting sales pressure, evasive answers, or a sense that they're more interested in the contract than the outcome—trust that instinct.
The right fractional CTO will make an immediate difference. They'll ask smart questions, offer useful perspectives, and make you feel like you're in capable hands. If you don't feel that in the interview, you probably won't feel it in the engagement.
Looking for fractional CTO support? Book a call with our team. We'll help you assess whether we're the right fit—and point you elsewhere if we're not.
