Fractional CTO for US Startups

Situations

Is This You?

If any of these situations sound familiar, let's talk:

Just raised seed funding but your technical co-founder left right before launch?

VCs asking technical questions you can't answer during due diligence?

Burning $50K/month on contractors who can't ship working software?

6 months from launch but still no clear tech strategy or architecture?

Engineering team promising features "next sprint" for the past 6 months?

Need to hire a CTO but can't afford $250K salary + equity right now?

The case

Why US Startups Bring In a Fractional CTO

Most US-based founders I work with come in asking the same thing: when should I hire a fractional CTO instead of waiting to hire a full-time one? Here are the three reasons that come up most.

Launch Your MVP Before Runway Ends

Get to market in weeks, not months. I help seed-stage startups ship fast and validate ideas before burning through capital.

Answer VC Technical Questions With Confidence

Navigate due diligence, defend your tech stack, and prove you can scale. I prepare the technical story investors actually probe.

Scale Engineering Without Burning Cash

Avoid $250K+ hiring mistakes. Get CTO-level strategy with no equity and no long-term commitment.

Background

About Me

I'm Ezequiel Actis Grosso, a technology leader with 25 years in software, from Buenos Aires to Miami, and from San Francisco to Sydney, across global corporations and fast-growing startups.

For the past decade I've worked with founders in Latin America and the United States, helping them move fast, find product-market fit and scale their B2B SaaS products, without the over-engineering that slows them down.

Ezequiel Actis Grosso

Fractional CTO

Lean Studio · LinkedIn

Architecture for AI products in production
Technical due diligence for investors
From zero to first customer with MVP delivery

In practice

Case Study: CTO for a TechBio AI Startup

CTO · MateBio

I led the transformation of raw biomedical knowledge graph data into a scalable, defensible, commercially viable platform. MateBio, a spin-off from the University of California, San Francisco, provided AI-powered tools that enabled wet lab researchers at biotech and pharma companies to explore complex biological relationships through natural language queries and interactive visualizations.

80+

integrated data sources

AWS + GCP

two clouds

Architected the core GraphRAG pipeline: a multi-tool LLM agent that turns natural-language biomedical questions into validated Cypher over a Neo4j knowledge graph spanning 80+ integrated data sources, with entity recognition, provenance tracking, and confidence scoring.
Built a hybrid entity-resolution engine that maps imprecise researcher terms ("p53", "breast cancer") to exact graph identifiers, fusing heuristic biomedical NER, type-scoped full-text and vector search, and small-model disambiguation.
Added a systems-biology analytics layer: Graph Data Science centrality (PageRank and personalized PageRank over pre-computed projections) plus a synthetic-EHR cohort service producing "signatures" that rank genes and pathways from clinical cohorts.
Built multi-modal data ingestion so researchers could bring their own data alongside the graph: PDF and URL document RAG, plus CSV and omics analysis with auto-generated mermaid diagrams.
Stood up the platform across two clouds (AWS and GCP, each running Neo4j and PostgreSQL) with Terraform-driven CI/CD, secure multi-tenant APIs, and a tested cross-cloud database migration path.

In practice

Case Study: MVP Delivery for a FinOps AI Startup

Lead & Architect · Xogito

I led the development of an AI-powered chatbot for a FinOps startup in Seattle. The platform helps enterprise teams attribute, budget, monitor, and optimize generative AI spend across providers.

1 month

to MVP

3

model providers

MVP delivered in one month by reusing existing front-end components and infrastructure, securing early customers and validating product-market fit without a full system rebuild.
Architected a multi-provider abstraction over OpenAI, Anthropic, and AWS Bedrock, routing each request to the best-fit model: reasoning, RAG, image generation.
Instrumented the chatbot as a representative GenAI application: the platform tracks provider usage, token consumption, and cost attribution across real application traffic.
Implemented token streaming, tool-call progress indicators, and persistent chat history to keep long, multi-step queries responsive and transparent.
Introduced workspace isolation and role-based access controls to support multi-tenant enterprise deployments from day one.

Track record

Earlier Work

VP of Engineering · Leapfactor

Fintech and Mobile Platforms

I led the build of a US–Mexico remittances wallet and the cloud platform behind mobile apps for Avon, L'Oréal, and AstraZeneca, running distributed teams across five countries. Compliance, cross-border payments, and shipping on a startup clock.

Director of Engineering · Cascade

Scaling a Global Engineering Org

I ran teams across Argentina, North America, and Australia for a strategy-software scale-up, introduced engineering metrics and a career framework, and sat on the global product leadership team.

Services for US Startups

Rapid MVP Development

Launch in 8-12 weeks. Enough product to learn from real users, without the architecture you would need at 100x.

Fundraising Tech Due Diligence

Prepare the stack for investor scrutiny: the architecture questions, the security posture, and the hiring plan they will probe.

B2B SaaS Architecture & Scaling

Multi-tenant systems that survive growth. Tenant isolation, usage-based billing, and a data model that does not need a rewrite at 10,000 users. The full playbook lives on fractional CTO for B2B SaaS.

Remote Team Building & Leadership

Hire and run engineering across US and LATAM time zones. I have done it with teams in Argentina, North America, and Australia.

Technology Stack Assessment

Audit the technical decisions before they get expensive. Independent recommendations, including when the answer is to leave it alone.

AI/ML Product Integration

Add AI features that hold up in production: RAG pipelines, agentic workflows, and the cost controls that keep the margin intact.

Formats

Investment Levels

Retainers run $5K–$15K a month, from advisory with a bounded MVP to an embedded CTO, and a tech assessment is a one-time $4,000. What each option includes is on the pricing page.

Next step

Let’s Build and Scale Your Startup

Not sure where to start with your tech challenges? I offer a comprehensive assessment to identify the roadblocks and opportunities that will take your product and team to the next level.

Book a Free 30-min Call Connect on LinkedIn

FAQ

Frequently Asked Questions

What fractional CTO services does a startup actually get?

Depends on how much of the CTO job you hand me. At the core it's technical judgment: architecture, build-vs-buy, and getting you through VC technical due diligence. Add a bounded MVP and I ship it, typically in 8-12 weeks. Go embedded and I build and run your remote engineering team across US and LATAM time zones. Retainers run $5K–$15K a month, from advisory with a bounded MVP to an embedded CTO, and a tech assessment is a one-time $4,000.

Do you take equity or just cash?

Cash only. I don't take equity because it keeps the relationship clean and flexible. You get CTO-level expertise without diluting your cap table, and you can scale the engagement up or down based on your needs.

Can you help us during fundraising due diligence?

Absolutely. I've helped multiple startups prepare for and navigate technical due diligence during Series A and Series B raises. I can document your architecture, defend your tech decisions, create investor-ready technical roadmaps, and answer VCs' technical questions with confidence.

What if we need to scale you to full-time during a critical launch?

Completely flexible. Many startups start with advisory work, scale up to near full-time during critical launches or fundraising, then scale back to ongoing strategic guidance afterward. The pricing adjusts based on time commitment.

How quickly can you start?

For urgent situations (technical co-founder left, investor deadline, critical launch), I can start within 48 hours. For planned engagements, typically 1-2 weeks from our initial call.

Will you help us hire a full-time CTO eventually?

Yes. Part of my role is helping you determine when you're ready for a full-time CTO, writing the job description, screening candidates, and ensuring a smooth transition. I've successfully transitioned several clients to full-time CTOs when the time was right.

What if we're not a fit after the first month?

All engagements are month-to-month with 30-day notice. If I'm not delivering value or it's not working out, you can end the engagement with no long-term commitment. Most clients extend because I focus on tangible outcomes from day one.

Do you work with remote teams across different time zones?

Yes. I specialize in distributed teams across US and LATAM time zones. I've managed teams in Argentina, Colombia, Mexico, USA, Australia and more. I'm comfortable with async communication and building strong remote engineering cultures.

How does a US company pay a fractional CTO based in Argentina?

The same way you pay any contractor. I invoice through a US company, and you pay against the invoice on your normal terms, with no special vendor setup, no foreign-payroll platform, and no FX exposure on your side.