In summary: A CTO as a Service costs 24 to 72k euros/year compared to 150-260k euros for an in-house CTO (excluding equity). It's the right choice for pre-Series A startups and tech teams under 10 people. Beyond that, an in-house CTO makes more sense. The hybrid approach (external CTO then internal recruitment) minimizes risks.
The dilemma every growing company faces
Your company has reached a stage where technology becomes strategic. You need senior technical leadership, but what form should it take? Hire a full-time CTO or engage a CTO as a Service?
This guide compares both approaches across every criterion that matters, with concrete 2026 figures.
Who is this guide for?
Non-technical founders, SMB CEOs, growing company directors — anyone who needs to make a structural decision about their technical leadership.
Cost comparison
This is often the first decision criterion. The gaps are significant.
In-house CTO: the real cost
| Item | Annual cost | |------|-----------| | Gross salary | 90,000 - 150,000 euros | | Employer charges (~45%) | 40,000 - 67,000 euros | | Benefits (health, meals...) | 3,000 - 8,000 euros | | Equipment and licenses | 3,000 - 5,000 euros | | Recruitment (agency, time) | 15,000 - 30,000 euros | | Annual total | 151,000 - 260,000 euros |
Source
According to the Apec 2025 barometer, the median salary for a CTO in France is between 110,000 and 130,000 euros gross annual. The ranges above include variations by company size and region.
Not counting equity (often 1-5% for a founding CTO) and the risk of a bad hire — estimated at 1.5x the annual salary.
CTO as a Service: flexible plans
| Plan | Annual cost | |------|-----------| | 2 days/week (most popular) | 48,000 - 72,000 euros | | 1 day/week | 24,000 - 36,000 euros | | One-off mission (3 months) | 15,000 - 30,000 euros | | Social charges | 0 euros (invoiced as a service) | | Recruitment cost | 0 euros |
Direct cost comparison
| Cost item | In-house CTO (median) | CTO as a Service (2 days/wk) | |-----------|----------------------|------------------------------| | Total annual cost | 200,000 euros | 60,000 euros | | Startup cost (recruitment) | 25,000 euros | 0 euros | | Financial risk on failure | 180,000 euros (severance) | 0 euros (simple stop) | | Time to operational | 3 to 6 months | 1 to 2 weeks |
Observed savings
The savings are significant: 60-80% reduction compared to a full-time position, for expertise that is often equivalent or even superior.
Comparing advantages
In-house CTO strengths
Full availability
Present daily, immersed in company culture, available for emergencies.
Long-term commitment
Aligned with the 3-5 year vision, emotionally and financially invested (equity).
Team leadership
Direct management, daily rituals, pair programming, junior mentoring.
Strong signal
Reassures investors and technical candidates during recruitment.
CTO as a Service strengths
Diverse expertise
Experience gained across multiple contexts: startups, scale-ups, enterprises, various industries.
Immediately operational
No probation period or 3-6 month ramp-up. Productive from week one.
Objectivity
External perspective without organizational bias. Able to say what no one internally dares to say.
Zero HR risk
No notice period, no severance, no termination procedure. Immediate stop or adjustment.
Head-to-head: visual summary
In-house CTO — Strengths
- Daily presence and cultural immersion
- Long-term commitment and loyalty
- Direct day-to-day team management
- Intimate codebase knowledge
- Strong signal for investors
In-house CTO — Weaknesses
- Very high annual cost (150-260k euros)
- 3-6 month recruitment timeline
- High risk in case of bad hire
- Vision limited to a single company context
- Heavy procedure in case of separation
CTO as a Service — Strengths
- 60-80% lower cost than full-time position
- Operational in 1-2 weeks
- Multi-industry and diverse expertise
- Total flexibility (adjustment, termination)
- Objectivity and external perspective
CTO as a Service — Weaknesses
- Part-time availability (not every day)
- Less immersed in company culture
- May be perceived as less committed
- Does not replace daily management for large teams
- No equity participation
When to choose an in-house CTO?
An in-house CTO is the right choice when:
Fundraising completed (Series A+)
You have the financial means for a C-level salary and investors expect a named CTO.
Tech = core business
SaaS, deeptech, platform: technology IS your product and requires continuous R&D.
Tech team of 10+ developers
Beyond 10 people, daily management requires a permanent presence.
Rapid growth planned
Team doubling in 12 months: you need a leader present every day to drive this growth.
When to choose a CTO as a Service?
An outsourced CTO is the right choice when:
Early stage (pre-seed / seed)
Every euro counts. You need senior expertise without burning your runway.
Small tech team (1-8 devs)
The team is self-sufficient day-to-day but needs strategic direction and guidance.
Transition underway
CTO departure, technology pivot, fundraising prep: an external CTO stabilizes the situation.
Specific expertise needed
Architecture, security, tech recruitment, audit: a scoped mission with a clear objective.
The hybrid approach: best of both worlds
More and more companies are adopting a hybrid approach that combines the strengths of both models:
Phase 1: Foundation (3-6 months)
CTO as a Service to lay the groundwork: architecture, processes, roadmap, hiring first developers.
Phase 2: Guided recruitment
The external CTO helps define the profile, participates in interviews, and validates the final candidate.
Phase 3: Progressive transition
Knowledge transfer over 1-2 months. The external CTO remains available for advice during the integration period.
Why it works
This approach minimizes risks: you hire with full knowledge (the tech is already structured), the in-house CTO arrives in a healthy environment, and the transition is supported.
Summary table
| Criterion | In-house CTO | CTO as a Service | |-----------|-------------|-----------------| | Annual cost | 150-260k euros | 24-72k euros | | Time to start | 3-6 months | 1-2 weeks | | Flexibility | Low | High | | Availability | Full-time | Part-time | | HR risk | High | None | | Industry expertise | One company | Multiple | | Commitment | Long-term | Adjustable | | Company culture | Full immersion | External view | | Objectivity | Limited (internal bias) | Strong (external perspective) | | Exit cost | High (severance) | None |
Frequently asked questions
How much does a CTO as a Service cost compared to an in-house CTO?
A CTO as a Service costs between 24,000 and 72,000 euros per year (1 to 2 days/week), compared to 150,000 to 260,000 euros for an in-house CTO (salary + charges + recruitment). Savings of 60 to 80%.
When should you choose an in-house CTO?
After Series A+ fundraising, when tech is the core business (SaaS, deeptech), with a team of more than 10 developers, or when rapid growth is planned.
When should you choose a CTO as a Service?
At the early stage (pre-seed/seed), with a tech team of 1 to 8 people, during transitions (CTO departure, pivot), or for specific expertise needs.
Can you combine both approaches?
Yes. The hybrid approach starts with a CTO as a Service to structure the tech (3-6 months), then recruits an in-house CTO with the external CTO's help, and finally ensures a progressive transition.
How long to make a CTO as a Service operational?
1 to 2 weeks, compared to 3 to 6 months for an in-house CTO (recruitment + probation + ramp-up).
What are the risks of a CTO as a Service?
The main limitations are part-time availability, less immersion in company culture, and no equity participation. These are offset by flexibility, reduced cost, and multi-industry expertise.
Our recommendation
There's no universal answer. The right choice depends on your maturity stage, budget, and objectives.
In 10 years of CTO consulting, I've seen dozens of companies make the wrong choice — often under investor pressure or by convention. The truth is that 80% of pre-Series A startups don't need a full-time CTO.
At Mag&Cie, we've been supporting startups and SMBs since 2015 as outsourced CTOs. We also help our clients recruit their in-house CTO when the time comes — and we ensure the transition.
Need personalized advice? Book a call for a free 30-minute conversation. We'll analyze your situation and recommend the most suitable approach.