A founder asks for "fractional CTO help" and gets sent three different proposals: one from a fractional CTO, one from a tech advisor, one from a CTO-as-a-service firm. They look superficially similar — senior engineering experience, monthly engagement, AI on the brief. Underneath, they solve different problems. Picking the wrong one is one of the more expensive mistakes a Series A or B company can make.
Tech advisor: 4–8 hours per month
An advisor gives you strategic input. They sit on a regular call with the CEO or the head of engineering, weigh in on architecture decisions, sanity-check vendor selections, occasionally introduce relevant talent. They don't touch the code. They don't manage the team. They typically have day jobs as full-time CTOs or VPEs at other companies.
Right fit: a pre-product founder, or a Series A team where the founding engineer is competent and just needs experienced perspective on big calls. Cheap, low-friction, useful.
Wrong fit: anywhere the team itself needs leadership. An advisor can't fix shipping velocity, can't run a hiring loop, can't be in the room when a difficult engineer conversation happens. Companies that hire an advisor when they need a fractional CTO usually realize the gap six months later — after a key hire fails or a project misses a quarter.
Fractional CTO: 30–80 hours per month, embedded
A fractional CTO embeds with your team. They attend standups, run 1-on-1s with engineers, design architecture, make hires, sit in on board meetings. They are functionally your CTO for the duration of the engagement — they just don't work for you full-time.
Right fit: 15–80 person companies that need real engineering leadership but aren't ready to commit to a $500K+ full-time hire. Or companies that need a specific transition (founding engineer to org, monolith to platform, pre-AI to AI-integrated) led by someone who's done it before.
Wrong fit: organizations that need 40+ hours per week of CTO availability — at that point you need full-time. And companies where the founder isn't actually willing to share decision-making authority — fractional CTOs need real authority to be useful.
CTO-as-a-Service: a firm assigning you a CTO + supporting team
Usually a consulting firm with a stable of CTOs and an offshore engineering bench. You get an account-CTO who runs the engagement, plus access to development capacity. Often pitched as "complete engineering leadership in a box."
Right fit: companies that need both engineering leadership and engineering capacity — especially greenfield builds where you don't have an existing team to integrate with. The bundled-team approach moves fast at the start of a project.
Wrong fit: companies with an existing engineering team. The CTOaaS model often clashes with in-house engineers, optimizes for the firm's preferred stack, and creates dependency on the firm even after the engagement ends. There's a reason most companies who go this route end up wanting to bring it all in-house within two years.
How to choose
Three questions. What's your team size? Pre-team → advisor or CTOaaS. Existing team → fractional. Do you need delivery capacity, or just leadership? Need capacity → CTOaaS. Have capacity, need leadership → fractional. How much continuity matters with your existing engineers? High continuity → fractional. Greenfield → either.
If you're at the deciding point, talk to us. We do fractional CTO engagements specifically — embedded, with your team, no offshore bench, no template stack.