What is a Fractional CTO?
Complete guide to fractional CTO roles: definition, responsibilities, when to hire, salary, and how fractional CTOs differ from full-time Chief Technology Officers.
Fractional CTO Definition
A fractional CTO is an experienced Chief Technology Officer who works part-time (typically 2-3 days per week) with multiple companies simultaneously, rather than as a full-time employee. Fractional CTOs provide strategic technology leadership, architectural guidance, engineering team building, and technical decision-making without the cost of a full-time hire.
Key Characteristics of Fractional CTOs
- Part-time commitment: 2-3 days per week on average (flexible)
- Multiple concurrent clients: Usually work with 2-3 companies simultaneously
- Senior experience: 15+ years in technology leadership roles
- Flexible engagement: Project-based or monthly retainer arrangements
- Remote-friendly: Majority of fractional CTO roles are fully remote or hybrid
What Does a Fractional CTO Actually Do?
Strategic Responsibilities:
- Set technology vision and strategy
- Define technical architecture and infrastructure
- Guide product roadmap from technical perspective
- Security, compliance, and scalability decisions
Team & Hiring:
- Build and scale engineering teams
- Technical hiring and interviewing
- Engineering best practices and processes
- Team mentoring and development
Hands-on Contributions:
- Code review and architecture guidance
- Technical problem-solving
- Technology evaluation and selection
- Performance optimization
When Should You Hire a Fractional CTO?
Fractional CTOs are ideal when:
- Series A/B stage: Growing teams needing senior technical guidance
- Building first engineering team: Need help with hiring and structure
- Technical debt: Need expert help addressing architecture issues
- New product launch: Guidance on technical approach and team
- Scaling challenges: Moving from startup to scale-up engineering practices
Fractional CTO vs Full-Time CTO
| Factor | Fractional CTO | Full-Time CTO |
|---|---|---|
| Cost | £180k-£280k/year (2-3 days/week) | £150k-£250k + equity |
| Availability | 2-3 days/week (flexible) | Full-time commitment |
| Experience | Very senior (15-20+ years) | Varies (5-20+ years) |
| Day-to-day | Strategic, mentoring | Strategic + hands-on coding |
| Commitment | Multiple companies | Single company focus |
Fractional CTO Salary & Day Rates
UK fractional CTO compensation:
- Day rate: £900-£1,400 per day
- Annual (2-3 days/week): £180,000-£280,000+
- FinTech premium: +10-15% (£1,000-£1,600/day)
- London premium: +10-15% vs regional