Marketer · Operator · Builder

Marvin builds
things.

Growth marketer and operator in the SF Bay Area. I build brands, businesses, and the systems that scale them — increasingly with AI doing the heavy lifting alongside me.

Growth & Paid Media Brand Strategy Founder Instinct
300+PARTNERSHIPS
17yrIN MARKET
2VENTURES BUILT
1EXIT
Work spanning food & beverage leaders, national franchises, education, and healthcare brands.
Brands I've helped grow
Marvin Fontanilla Placeholder — swap in /public/portrait.jpg
Hi, I'm Marvin

An entrepreneur, marketer, and unshakable optimist.

I believe in the good in people and the compounding power of showing up. I've spent my career growing brands — some you know, some you've eaten — and building ventures of my own along the way.

Today I lead growth at a full-service digital marketing agency in the Bay Area, working across food & beverage, education, home services, and healthcare. I'm not an AI tourist — I build agents and skills that do real work: research, reporting, creative. And it shows up in the results.

Off the clock: biking, coffee culture, markets, and time with family.

How I work

Strategy, with an unfair advantage.

🧭

Audience-first strategy

I lead with the person and their real problem — not the product. Clarity over cleverness, specificity over noise, outcomes over features.

🤖

AI-built systems

I design agents and repeatable skills that do real work — research, reporting, creative iteration — so campaigns move at a pace teams can't match manually.

📈

Measurable growth

Across paid media, SEO, and lifecycle, I've helped brands turn attention into revenue. The clients stay nameless here — the results don't.

The stack

Tools I build & deploy with.

A working set of the platforms, ad tools, and AI systems I run day to day — from the ad managers to the CMSs to the agents doing the quiet work.

Cloudflare Cloudflare
GitHub GitHub
Astro Astro
WordPress WordPress
Ix Ingeniux
Squarespace Squarespace
Claude Claude
Meta Ads Meta Ads
TikTok Ads TikTok Ads
Google Ads Google Ads
Google Analytics Google Analytics
Mailchimp Mailchimp
Klaviyo Klaviyo
HubSpot HubSpot
Ahrefs Ahrefs
Sw SimilarWeb
Sm Supermetrics
Motion
Canva Canva
Figma Figma
Notion Notion
Asana Asana
Slack Slack
Hootsuite Hootsuite
Gr Granola
Google Workspace Google Workspace
The résumé, minus the boredom

Work & ventures.

// Work (Present)

Director of Marketing

Full-service digital marketing agency · SF Bay Area

Leading paid media and growth for a portfolio of brands across food & beverage, education, home services, and healthcare — and pushing the whole shop toward AI-assisted execution.

// Side hustle (Exit)

Pop Up Gelato — Acquired

Co-founded · San Francisco roots, locations across LA & Orange County

A gelato brand I co-founded and grew into a multi-location California operation — then sold to Phthalo Investments. Built on the lessons from an earlier failure, into something worth acquiring.

See it on Crunchbase →
// Side hustle (Failed)

Frozen Dessert Venture — Fresno & Modesto

A past life, and a good story

In a past life I operated two frozen dessert shops in Fresno and Modesto, CA. It didn't make it — and progress is sometimes disguised as failure. I'd do it again.

Watch the Modesto launch video →
Nights & weekends

Side projects I'm building.

WalkSteady

WalkSteady.app

A product I'm building to help people move better and stay steady on their feet. Designed, shipped, and iterated with AI in the loop.

WEB APP · IN DEVELOPMENT
Stock App

Stock Analysis App

An investing tool that runs 10 distinct modes of analysis — from buy/sell calls to risk, technicals, and long-term thesis — turning market data into a real decision.

FINANCE · 10 ANALYSIS MODES
Off the clock

What I'm into.

🤖
AIAgents & skills
📊
FinanceMarkets & investing
🎨
DesignProduct & brand
🚲
BikingMiles to clear the head
👨‍👩‍👧
FamilyThe whole point
Coffee cultureThird-wave everything
The blog

Writing & field notes.

Topics may or may not include: marketing strategy, AI in the real world, investment theses, and things that I like.

All posts →

Let's build something.

Working on a brand, a growth problem, or an AI system you can't quite crack? I'd love to hear about it.

Say hello →