Brian MacDonald
Founder & Lead Engineer.
I'm an engineer and an operator. I've spent 20 years building businesses and running marketing across the tech industry — and the last few architecting AI systems that help companies scale faster than their headcount can. I'm now building all of it in public.
I grew up in Northern California in a family rooted in technology. I spent 8 years at American Express, built and exited an e-commerce business in my twenties, and ran a portfolio of marketing operations and lead-gen work across dozens of companies in the years that followed. The thread never changed: build things that work, and build the marketing engine that grows them.
Today my focus is Mavrick — an AI coworker I built end to end, from the infrastructure up. It runs marketing and lead generation natively in Slack, connecting to the 3,200+ tools a modern team already uses across CRM, sales, and analytics.
Building in public means showing the calls, not just the credits. A few of the decisions behind Mavrick:
- Predictable AI cost. I put a hard spend cap and model-tiering on the whole system — the cheap model does the routine work, the expensive one only when it earns it. AI bills don't get to surprise you.
- It asks before it acts. Anything that spends money or sends a message waits for a human's yes. The agent can never quietly do something you didn't approve.
- It can't double-act. Built so a hiccup can't make it run the same job twice — the unglamorous engineering that keeps an autonomous system trustworthy.
- Compliant by construction. Cold outreach follows the rules in code, not in a policy doc someone forgets.
- Pointed at the money. The hard part isn't automating everything — it's knowing which work quietly costs you revenue and putting AI exactly there.
- Shipped, not slideware. It's live in production — Slack-native, free to start, SOC 2 underway.
Mavrick is the proof point for everything I believe about how AI belongs inside a business: pointed at the money, integrated with the tools the team already uses, and engineered to last. Mavrick is the product. The work behind it — and the marketing operation around it — is who I am.
Based in Orange County, California.