A fractional CTO is a Chief Technology Officer who works with your business part-time — typically 1–3 days per week — while serving other clients simultaneously.
You get executive-level technical leadership without the full-time salary, equity, and commitment that comes with a permanent hire.
The fractional executive model has grown significantly since 2019, with the number of roles doubling since 2022. Industry analysts expect around 30% of midsize enterprises will have at least one fractional executive on retainer by 2027.
This guide covers when a fractional CTO makes sense, what they actually do, what they cost, and how to get the most from the relationship.
What a Fractional CTO Does
Technical Strategy
- Defining technology roadmap and priorities
- Making build vs. buy decisions
- Evaluating and selecting technology platforms
- Aligning technical decisions with business goals
The CTO answers: “What should we build, on what, and in what order?” Not the tactical how — the strategic what and why.
Architecture and Technical Direction
- Designing system architecture for scale
- Reviewing and improving existing architecture
- Identifying and addressing technical debt
- Setting coding standards and practices
Bad architecture decisions compound. A fractional CTO catches problems before they become expensive rewrites.
Team Leadership
- Hiring and evaluating engineering talent
- Managing and mentoring development teams
- Setting performance expectations
- Building engineering culture
Someone needs to lead the engineers. The fractional CTO provides that leadership without full-time overhead.
Vendor and Partner Management
- Evaluating development agencies
- Managing outsourced development relationships
- Negotiating technology contracts
- Assessing technology vendors
Most businesses use external partners for some development. The CTO ensures they’re actually good — and holds them accountable.
Executive Translation
- Communicating technical progress to non-technical stakeholders
- Representing technology at board level
- Supporting investor conversations (especially technical due diligence)
- Managing stakeholder expectations
Founders shouldn’t need to understand Kubernetes to know if engineering is on track. The CTO bridges that gap.
Risk and Compliance
- Identifying and mitigating technical risks
- Ensuring security best practices
- Managing regulatory compliance (GDPR, industry-specific)
- Disaster recovery and business continuity
Technical failures have business consequences. The CTO owns this risk.
What a Fractional CTO Doesn’t Do
They don’t write code. Some fractional CTOs can code, but that’s not what you’re paying for. If you need developers, hire developers.
They don’t manage day-to-day delivery. Sprint planning, ticket grooming, and daily standups are typically VP Engineering or Tech Lead work. The CTO sets direction; others execute.
They don’t replace your development team. The CTO leads the team, not substitutes for it. If you have no developers, hiring a CTO first is backwards.
They don’t work full-time. The model only works if the CTO focuses on high-leverage activities. Constant firefighting means something’s wrong.
When to Hire a Fractional CTO
You’re a Non-Technical Founder Building a Tech Product
You have a vision but not the technical expertise to evaluate whether it’s being built correctly. Developers tell you things are “on track” but you can’t verify it.
A fractional CTO provides the technical judgment you lack.
Your Development Team Needs Leadership
You have 3–15 developers doing good work, but nobody setting direction. Technical decisions get made ad hoc. Architecture is whatever the most senior developer thinks.
A fractional CTO provides strategic leadership without promoting someone who isn’t ready.
You’re Preparing for Fundraising
Investors will ask technical questions. They’ll want to understand your architecture, your roadmap, your technical team. “It works” isn’t enough.
A fractional CTO prepares you for technical due diligence and provides credibility in investor conversations.
You’re Scaling From MVP to Production
The code that got you to product-market fit probably won’t scale. Architecture decisions that were fine at 100 users break at 10,000.
A fractional CTO identifies what needs to change before it becomes a crisis.
Your Technical Debt Is Becoming Unmanageable
Every new feature takes longer than the last. Bugs multiply. Developers spend more time fixing than building.
A fractional CTO creates a technical debt strategy — what to fix, what to live with, and in what order.
You Can’t Afford (or Find) a Full-Time CTO
Senior CTOs command £150,000–£250,000 salaries, plus benefits, plus equity. Recruiting takes 4–6 months.
A fractional CTO provides the same capability at 40–60% of the cost, available within 2–4 weeks.
When NOT to Hire a Fractional CTO
You need full-time technical leadership. If you have 20+ engineers, complex products, or enterprise customers expecting constant technical engagement — fractional probably isn’t enough.
You need developers, not a leader. If your problem is “we need to build things” rather than “we need technical direction” — hire developers first.
You have no budget for execution. A fractional CTO costs £4,000–£8,000/month. If that’s your entire tech budget, you’ve got no money for the work they’re directing.
You want someone to code your MVP. Hire a dev agency or technical co-founder. CTOs direct; they don’t deliver code.
You’re not ready to make decisions. Fractional CTOs recommend. Someone needs to approve and act. If your business can’t make decisions quickly, the relationship stalls.
The Different Types of Fractional CTOs
Not all fractional CTOs are the same. Match your needs:
Product CTO
Focused on product development, feature prioritisation, user experience alignment with technical capabilities.
Best for: Product-led companies, SaaS businesses, consumer tech.
Platform CTO
Focused on infrastructure, scalability, reliability, DevOps, and technical operations.
Best for: High-traffic platforms, B2B infrastructure, companies with significant scale challenges.
AI/ML CTO
Specialised in artificial intelligence, machine learning, and data-intensive applications. Commanding 25% premium over generalist rates.
Best for: AI-native products, data science teams, companies integrating AI into core offerings.
Security CTO
Focused on information security, compliance, and risk management. Often combined with CISO responsibilities.
Best for: Regulated industries, companies handling sensitive data, enterprise sales.
Transformation CTO
Focused on modernisation, technical turnarounds, and major platform migrations.
Best for: Companies with legacy systems, technical debt crises, or post-acquisition integration.
UK Pricing: What to Expect
Day Rates by Company Stage
| Context | Day Rate Range |
|---|---|
| Seed stage startups | £800–£1,200 |
| Series A companies | £900–£1,300 |
| Series B+ companies | £1,100–£1,600 |
| Enterprise (large scale) | £1,000–£1,400 |
| Agencies/consultancies | £700–£1,100 |
Specialist Premiums
| Specialisation | Day Rate | Premium vs. Generalist |
|---|---|---|
| AI/ML CTO | £1,200–£1,600 | +25% |
| Security/CISO | £1,100–£1,500 | +15–20% |
| Platform CTO | £1,000–£1,400 | Baseline |
| Product CTO | £950–£1,350 | Baseline |
Retainer Models
| Engagement Level | Monthly Cost | Typical Commitment |
|---|---|---|
| Advisory only | £1,500–£3,000 | 4–8 hours/month |
| Light engagement | £4,000–£6,500 | 1 day/week |
| Standard engagement | £6,000–£10,000 | 2 days/week |
| Heavy engagement | £10,000–£15,000 | 3 days/week |
Geographic Variation
| Location | Rate Adjustment |
|---|---|
| London | +15–20% |
| Manchester, Bristol, Edinburgh | Baseline |
| Remote UK | -5–10% |
Fractional CTO vs. Alternatives
vs. Full-Time CTO
| Factor | Full-Time CTO | Fractional CTO |
|---|---|---|
| Annual cost (total) | £440,000–£845,000* | £36,000–£120,000 |
| Availability | 5 days/week | 1–3 days/week |
| Hiring timeline | 4–6 months | 2–4 weeks |
| Equity expectations | Significant (1–5%) | Usually none |
| Experience breadth | One company | Multiple companies |
*Includes salary, NI, benefits, recruitment fees, potential equity dilution
Choose full-time when: 20+ engineers, complex technical products, enterprise customer requirements, Series B+ with runway.
Choose fractional when: Earlier stage, smaller teams, need expertise without commitment, can’t afford/find full-time.
vs. Development Agency
| Factor | Agency | Fractional CTO |
|---|---|---|
| Focus | Delivery/execution | Strategy/direction |
| Accountability | Features delivered | Technical outcomes |
| Hourly cost | £75–£200/hour | £150–£350/hour |
| Monthly cost | £10,000–£50,000 | £4,000–£15,000 |
Best approach: Use both. Fractional CTO provides oversight and direction; agency provides hands. CTO ensures agency quality and holds them accountable.
Common mistake: Using an agency with no technical oversight. Agencies are incentivised to build; not to question whether something should be built.
vs. VP Engineering
| Factor | VP Engineering | Fractional CTO |
|---|---|---|
| Focus | Engineering management, delivery | Technical strategy, architecture |
| Team size ownership | 5–50+ engineers | Advisory/direction |
| Day-to-day involvement | High | Low |
| Strategic involvement | Medium | High |
Best approach: Many companies benefit from both — full-time VP Engineering for delivery management, fractional CTO for strategic direction. This is common in Series A/B companies.
The First 30 Days
Here’s what a typical fractional CTO engagement looks like at the start:
Week 1: Discovery
- Deep dive into business context, goals, and constraints
- Review existing architecture and codebase
- Meet development team members individually
- Understand current processes and tools
Week 2: Assessment
- Technical audit and architecture review
- Identify risks, debt, and opportunities
- Evaluate team capabilities and gaps
- Review vendor relationships and contracts
Week 3: Strategy Development
- Draft technical roadmap aligned with business goals
- Prioritise initiatives (quick wins vs. long-term investments)
- Define success metrics
- Identify resource requirements
Week 4: Alignment and Planning
- Present findings and recommendations to leadership
- Align on priorities and trade-offs
- Establish ongoing cadence and communication
- Set 90-day objectives
Don’t expect transformation in month one. Good fractional CTOs invest in understanding before acting.
Common Engagement Models
The Hybrid Model: Fractional CTO + Agency
Structure:
- Fractional CTO: 1–2 days/week (£4,000–£8,000/month)
- Development agency: £15,000–£40,000/month
- Total: £19,000–£48,000/month for full technical capability
Why it works:
- CTO provides direction agency needs
- CTO evaluates agency quality objectively
- Clear separation of strategy and execution
- Flexible scaling of execution capacity
Watch out for:
- Agency bypassing CTO to founders
- CTO not having enough visibility into agency work
- Blame games when things go wrong
The Team Builder Model
Structure:
- Fractional CTO: 2–3 days/week initially
- CTO hires and builds internal team
- CTO reduces involvement as team matures
- End state: Internal team with CTO advisory
Why it works:
- CTO applies experience to hiring decisions
- Team built to CTO’s standards
- Smooth transition to independence
- Long-term cost efficiency
The Turnaround Model
Structure:
- Fractional CTO: 3–4 days/week for 3–6 months
- Intensive technical transformation
- Clean up debt, fix architecture, improve processes
- Transition to lighter engagement
Why it works:
- Concentrated expertise when you need it most
- Clear timeline and objectives
- Higher intensity than typical fractional engagement
- Defined end state
How to Find a Good Fractional CTO
Sourcing
Referrals — Ask other founders, VCs, and technical leaders. Best fractional CTOs are often fully booked via word-of-mouth.
Fractional executive platforms — CTO Partners, Fractional.work, and similar platforms vet and match CTOs.
LinkedIn — Search “fractional CTO” + your industry or technology stack. Review their content and recommendations.
VC networks — If you have investors, ask their portfolio network. VCs see many fractional CTOs across companies.
Evaluation Questions
- “Walk me through your approach to inheriting a codebase you didn’t build.”
- “How do you balance technical debt reduction with feature development?”
- “Describe a time you recommended NOT building something.”
- “How do you evaluate and improve a development team?”
- “What would you do in the first 30 days here?”
Red Flags
- Wants to rewrite everything immediately — Good CTOs work with what exists
- Can’t explain trade-offs — Every decision has them; CTOs should articulate both sides
- No references from similar stages — Unproven in your context
- Promises specific outcomes before understanding context — Overpromising
- Unavailable between sessions — Fractional doesn’t mean absent
Making the Relationship Work
Communication Rhythm
Weekly: 30-minute status sync. What happened, what’s blocked, what’s needed.
Bi-weekly: Deeper technical review. Architecture decisions, team performance, roadmap progress.
Monthly: Executive summary. Progress against goals, key decisions, recommendations.
Quarterly: Strategic review. Is the approach working? What’s changing? What’s next?
Getting Maximum Value
Give access. Codebase, infrastructure, documentation, team members, stakeholders. CTOs can’t lead blind.
Make decisions. When the CTO recommends something, decide quickly. Delayed decisions waste expensive time.
Follow through. If you agree to address technical debt, actually allocate the resources.
Be honest about constraints. Budget limits, timeline pressures, political realities — share them.
Trust technical judgment. You hired an expert. Let them advise.
Expected Outcomes
After 6–12 months with a good fractional CTO:
Technical clarity — Documented architecture, understood by the team.
Reduced risk — Technical debt under control, security addressed, scale planned.
Better team — Engineers hired, developed, and retained effectively.
Investor confidence — Technical story that supports fundraising.
Informed decisions — Technical trade-offs understood by leadership.
Execution improvement — Features shipping faster with fewer bugs.
If you’re not seeing these outcomes, something’s wrong with the engagement, the CTO, or the business’s readiness for technical leadership.
FAQ
What’s the difference between a fractional CTO and a technical advisor?
Advisors provide occasional input (a few hours per month). CTOs provide ongoing leadership (1–3 days per week). Advisors answer questions; CTOs drive outcomes.
Can a fractional CTO help us raise funding?
Yes. They prepare technical due diligence materials, attend investor meetings, and answer technical questions credibly. This is especially valuable for non-technical founders.
How long do fractional CTO engagements last?
Typically 6–24 months. Some become ongoing advisory relationships. Others end when the company hires full-time or outgrows the model.
Should we give a fractional CTO equity?
Not typically. The fractional model is designed for flexibility; equity creates lock-in. Some may accept small stakes (0.1–0.5%) but it’s not standard.
What if we have a technical co-founder but they’re not CTO-level?
Common situation. The fractional CTO can mentor the co-founder, provide strategic direction, and fill capability gaps — without threatening the co-founder’s role.
Related: Fractional CTO for Startups: Is It Right for Your Stage?
