Fractional CTO for Founders & Teams That Need Real Execution

I help startups, agencies, and growing companies design the right tech stack, build strong engineering teams, and ship scalable, AI-ready products — without the cost of a full-time CTO.

Let’s Talk

Who I Work With

Startup Founders

Build MVPs and scale without costly technical mistakes.

Advertising & Creative Agencies

CTO-level support for platforms, integrations, and advanced builds.

Growing Companies

Stabilize, scale, and modernize your tech stack.

Services

Fractional CTO

Executive technical leadership.

Architecture

Scalable system design.

Team Building

Hiring and mentoring.

AI Integrations

Practical AI systems.

APIs

Custom and Secure integrations.

SSO

Enterprise identity systems.

DevOps

Cloud & CI/CD.

Multimedia Production

Creative & Technical direction.

Application Development

Across different devices.

How It Works

Discovery Align goals and vision.
Planning Define architecture and roadmap.
Execution Lead hands-on delivery.
Scale Grow or transition.

Why Work With Me

25+ years building real-world applications across SaaS, AI, immersive (VR/AR), gaming and ad tech.

CTO/Lead for platforms and applications used by Comcast, ADT, Dell, and more.

Technical leadership and hands-on engineering experience across organizations such as Adobe, Konami, Zynga, and CBS Interactive (CBS News, CBS Sports) and more.

Beyond engineering leadership, I bring a strong background in design, animation, and multimedia production. This allows me to communicate effectively with advertising and creative agencies, translate concepts into technical execution, and ensure that visual intent and performance remain aligned.

Let’s Build Something Solid

Email: rexcartagena@gmail.com

Mobile: 415 420 4098