Fractional CTO: When the Model Actually Works

Fractional CTO has become a buzzword. Most arrangements fail because nobody defined what 'fractional' means. Here's the version that actually delivers.

"Fractional CTO" gets thrown around as if it means one thing. It doesn't. I've seen and run multiple flavors. Three patterns work. The rest fail.

Pattern 1: Founding CTO before the founding CTO

Setup: Pre-seed or seed startup, non-technical founder, 0-2 engineers. Fractional CTO is the technical decision-maker for 3-9 months until a full-time CTO is hired.

What I deliver:

• MVP architecture decisions (stack, data model, deployment)
• Hiring the first 1-2 engineers
• Technical due diligence on investor questions
• Setting up engineering practices that scale

Time commitment: 1-2 days/week.

When it ends: When the company hires a full-time CTO. I do the handover.

This works because the founder needs senior judgment without needing a full-time hire. I've run this version 4 times. All four hired full-time CTOs within 9 months.

Pattern 2: Senior advisor / coach to existing CTO

Setup: Series A or B startup, existing CTO who's stretched. Fractional advisor as a sounding board on architecture, hiring, and difficult calls.

What I deliver:

• Weekly 1-1 with CTO
• Quarterly architecture reviews
• Available for tough calls (incidents, escalations)

Time commitment: 4-8 hours/month.

When it ends: Open-ended. I have a few of these that have run 18+ months.

Pattern 3: Project-bounded fractional

Setup: Established company has a specific technical project with risk (modernization, ML build-out, scaling crisis). Fractional CTO leads the project end-to-end.

What I deliver:

• Project plan, architecture, milestones
• Hands-on coding for the gnarly parts
• Mentoring the in-house team

Time commitment: 2-4 days/week for the duration of the project.

When it ends: Project completion + 4-6 weeks of handover.

What doesn't work

• "We need a CTO sometimes." Vague. Both sides feel undelivered.
• "Fractional CTO" as a title for occasional advice. Shouldn't bill at CTO rates if you're an advisor.
• Multiple fractional CTOs at the same company. Too many cooks. I won't take an engagement where another fractional is already in the role.

Pricing reality

For senior engineers running fractional CTO engagements in 2025:

• Pattern 1: $8-15K/month
• Pattern 2: $2-5K/month
• Pattern 3: project-based, typically $40-150K

If you're paying less than these, you're getting an advisor or a senior engineer, not a fractional CTO. That's fine - just call it what it is.

When I take on engagements

I'm currently taking pattern 1 and pattern 3 engagements. Drop me a line if you're considering one.