Meet Marc Bernstein: Founder and CEO of Balto and Missouri Startup Weekend Mentor

Marc Bernstein has always been a builder. Born in Washington, D.C., Marc spent his childhood building PowerPoint games and crafting mousetraps out of popsicle sticks. That curiosity followed him to Washington University in St. Louis, where he studied entrepreneurship and marketing—and more importantly, began testing ideas in the real world.

One of his first ventures, DoorStep Fitness, brought personal training services directly into people’s homes. It was scrappy, hands-on, and very real-world. But it was in sales—specifically during a call where he blanked on how to handle a customer objection—that the spark for Balto was born. After the call, he hacked together a simple Excel macro to guide himself through tough conversations. That small tool would eventually evolve into Balto: a real-time AI platform that now powers over 350 million conversations and helps thousands of sales and support reps communicate better.

Under Marc’s leadership, the company raised more than $60 million in venture funding and expanded its customer base across industries. One of the biggest milestones, Marc notes, was building a real-time AI prototype capable of guiding calls without delay—“a game-changer,” he says.

But Marc’s success isn’t just about code and capital. He’s a creative, reader, chess player, and artist. He makes time for long walks and writes poetry. And when he talks about AI, he doesn’t just talk about productivity—he talks about people. "As AI becomes increasingly powerful, we will value our abilities less and our human experience more,” he reflects.

That human-first philosophy drives how he leads Balto and how he mentors. His advice to new founders is straightforward: talk to your customers, validate early, and focus on solving a real problem—not just building something cool.

He also knows when to get out of the way. “Letting go was the hardest part of scaling,” Marc admits. “As a founder, you’re used to being in the trenches. At some point, you have to trust your team.”

Now, as a mentor for Missouri Startup Weekend, Marc brings his full self—technical chops, founder intuition, and creative energy—to help the next wave of builders get their ideas off the ground. Whether he's talking AI, growth, or good coffee, he’s there to help teams move faster and think sharper.

Q&A

Balto has evolved from a personal tool to a full-scale AI platform. What were some pivotal milestones in that transformation? “So many! A few big ones stand out: 

• Our first real-time AI prototype. We proved we could listen to calls live and guide reps without delay. Game-changer.
• First major customer. Seeing Balto in action at scale validated everything.
• Our pivot to compliance & QA automation. It wasn’t just about helping reps talk better, it was about helping companies run better.”

What’s something surprising you’ve learned from analyzing over 350 million conversations? “People think sales and support are all about what you say, but it’s just as much about when you say it. Timing changes outcomes. For example, reps who introduce pricing too early in a sales call convert at lower rates. Small shifts in phrasing, pauses, and confidence make an enormous difference.”

Looking back, what’s something you wish you’d done differently? “I wish I had hired senior leadership earlier. Bringing in experienced execs helped us level up fast. I wish I had avoided spending too much time on features customers said they wanted but didn’t actually use. You have to validate demand before you build.”

What’s the first thing you try to understand when mentoring a founder? “I try to figure out if they’re solving a real problem. Not just something that sounds cool, but something painful enough that customers will pay for it.”

If you could give one piece of must-know advice to a first-time founder, what would it be? “Talk to customers way more than you think you need to. Your idea isn’t what matters—your customers’ problems are.”

You get to ban one startup buzzword forever—what is it? “Synergy. Just say collaboration like a normal person.”

Go-to ice cream flavor? “Cookies & cream. No contest.”

You get one app for the next month—what is it? “Audible, hands down. If I’m stuck with just one app, I want something that keeps me learning, entertained, and maybe even a little smarter by the end of the month.”

What excites you most about Missouri Startup Weekend? “The energy. Every year, you see founders go from idea to execution in a single weekend. That’s startup magic.”