Founder Friday: Andrei Negrau & Lisa Popovici, Co-Founders of Siena✨
Issue #53
Founder Friday is a content series from SuperAngel.Fund that highlights companies across our portfolio and the inspiring founders behind them.
SuperAngel.Fund is an early-stage fund led by Ben Zises that invests in Consumer, PropTech & Future of Work. So far, we have invested over $20m into 100+ companies. Apply to invest with us by clicking here.
In our 53rd edition we are featuring Andrei Negrau and Lisa Popovici, co-founders of Siena, an empathetic and autonomous customer service platform designed for commerce✨.
Andrei and Lisa are serial entrepreneurs with a passion for eCommerce and AI. While these Romanian-born founders have spent nearly all of their professional lives building startups in this space, it wasn’t until they surveyed hundreds of brand owners in 2022 that they discovered a massively growing pain point destined to be solved: As AI became more ubiquitous, merchants were eager to implement it into their customer service workflows. However, nearly all were extremely hesitant of doing so at the risk of jeopardizing their authentic voice and turning off customers.
Given their backgrounds, Andrei as a technical engineer at the forefront of the eCommerce & AI revolution, and Lisa as a growth marketer and sales leader, the two realized they were uniquely qualified to create the solution. One that would provide both an excellent customer experience and maintain a brand’s distinct identity.
Enter Siena, the world’s first autonomous AI Agent that can fully resolve customer service interactions with no human in the loop. Unlike chatbots and other similar options before it, Siena allows brands to automate up to 90% of conversations across all channels such as email, SMS, live chat, social media DMs and comments with zero backlogs and 24/7 coverage. Plus it can do it in 100+ languages and entirely in each individual brand’s voice. By combining the best of human empathy and intelligent automation, Siena transforms how brands engage with customers, turning lengthy interactions into low-cost opportunities to acquire, up-sell and retain.
And just as you would expect, Siena integrates seamlessly with dozens of partners like Shopify, Gorgias, Zendesk, Kustomer and more, removing countless hours of administrative tasks. As a result of its automation, Siena empowers brands to upskill their talent to focus on more strategic growth and innovation initiatives.
Siena is an empathetic and autonomous customer service platform designed for commerce ✨
Given how transformative Siena is, it is no surprise that they have seen explosive growth in the past two years, capturing the attention of leading brands such as: Simple Modern, Coterie, Bandit, Madhappy, Brooklinen, Eight Sleep, and MUD\WTR to name a few of their customers.
As AI adoption continues, my bet is that Siena will remain at the forefront.
You can book a demo to learn more about their offering and see what Andrei and Lisa have to say in this week’s Q&A 👇.
Describe your company in 5 words or less?
Andrei: Siena is the First Autonomous CX Agent.
Lisa: The Empathic AI Agent for CX.
What was your primary motivation for starting your business?
Andrei: I saw how broken customer service was becoming. Companies were choosing between two bad options: cheap bots that frustrated everyone, or throwing more humans at the problem. Neither worked. The interesting thing wasn't that AI could handle customer service - it was that AI could actually make it better than human-only service. Not just faster or cheaper, but genuinely better. More consistent. More empathetic. Available instantly at 2am on a Friday. But it had to be done right. Not another chatbot pretending to be human. Something that could actually understand what customers need and solve their problems in a way that builds a relationship over time, doesn't just deflect a ticket. That's what got me excited - building an AI that makes both customers and service teams think 'finally’, someone got this right.
Lisa: I wanted to create something that truly makes a difference in people's lives. The best part is we impact both worlds: the business and the end shopper. When we started Siena, it was about solving a real pain point we experienced firsthand—scaling customer experience without losing the human touch. I’m passionate about building things, and after years of trial and error in eCommerce, I realized that helping brands connect with their customers in a more meaningful way and be able to do it at scale is what drives me. I’ve always been drawn to challenges that combine empathy with innovation, and Siena was born from that motivation.
What new product/feature are you most excited about and why?
Andrei: I'm excited about our AI Reasoning architecture. Here's what's wrong with most AI customer service AI agents: It's a black box of hope and prayer. You input a customer problem, cross your fingers, and pray the AI doesn't hallucinate. That's insane for enterprise CX. At Siena, we've built something radically different. Siena shows its work - every decision, every calculation, every policy interpretation is visible and traceable. If your AI agent can't explain exactly why it offered a specific refund or how it interpreted your return policy, you don't really have an enterprise solution - you have an expensive guess machine. We built reasoning into our core architecture because that's the only way AI should operate in business-critical environments. Everything else is just playing pretend with customer trust.
Lisa: I’m most excited about the reasoning feature we recently launched. It’s a breakthrough in making AI explainable and trustworthy for enterprise operations. Traditionally, AI has been a black box—you’d get an answer but have no idea how or why it arrived at that decision. With Siena reasoning, every step of the AI's process is visible and documented. it’s designed to show its work, explaining which policies it applied, what trade-offs were made, and even why certain decisions might need human input. This transparency transforms how businesses use AI, giving them confidence to scale it across their most critical customer interactions. It’s a feature that not only enhances performance but builds trust.
What piece of advice would you give an entrepreneur starting a business today?
Andrei: Counterintuitive truth about starting a business today: Your biggest advantage is staying small and focused longer than anyone else is willing to. Pick a vertical so specific it almost feels like a mistake. Not 'SMB software' specific. Think 'AI scheduling software for independent tattoo artists' specific. When you focus on solving one precise problem for a small group, you start seeing things nobody else can see. Your product doesn't just work - it feels inevitable for that segment. Your early customers become evangelists because you understand their world better than they do. The magic happens when you resist the urge to expand too quickly. You'll want to serve different customers, add more features, tackle adjacent markets - this is where most founders slip. They mistake early success in one vertical as a signal to expand horizontally. Don't. Instead, go deeper. When adjacent markets start pulling you in - not when you push your way in - that's when you expand. This isn't just patience. It's strategic advantage.
Lisa: Just start, you'll figure it out along the way.
What do you love to do in your free time?
Andrei: I like to get into a flow state - whether that's running, riding my motorcycle, or going Othership Manhattan (love that place). Some of my best ideas for Siena surface when I'm moving. Not when I'm staring at a screen trying to force them. I'm always tinkering with something. Since starting Siena it's mostly AI models - can't help myself. After enough interactions with them, you start noticing patterns and behaviors that tell you exactly how they think. I find that fascinating.
Lisa: Workout, run, spend time with my Cavalier King Charles - Jazz, meet friends, visit museums, go on walks!
What is the most interesting place you’ve visited recently and why?
Andrei: Argentina. I spent a few weeks in Buenos Aires. The city's story is fascinating - 40,000 people in 1800 grew to 1.3 million by 1910, largely from Italian immigration. You can still feel that influence today. Walking through Buenos Aires, you realize pretty quickly why it's called the Paris of South America. And then there's the buses - you have to see them to understand what I mean. It's one of those city quirks that's impossible to explain.
Lisa: Paris is my favorite city after New York City. It's my second home. When I'm in Paris I feel like I'm living in the book I'm writing at the same time, helps me slow down, have different perspectives on life, and immerse myself in the art, history and beauty of the city. It's always been interesting to see how people live life there and what they value most: friendships, having a good time and enjoying the small things.
What is your favorite app or tool in your work life and in your personal life?
Andrei: Apple Notes. I know it sounds boring - there are a thousand note apps with fancier features. But it's fast, syncs everywhere, and search is instant. I dump everything in there - work ideas, personal stuff, random thoughts.
Lisa: Perplexity - my new search engine great for digging into my curiosities and being able to rely on the answers and sources I'm getting as results.
What do you want to be when you grow up (besides a successful founder)? 😊
Andrei: I want to look back and know I gave it everything.
Lisa: A lot of things! dancer, actress, wedding planner! movies always inspired me, I'm a big cinephile.
What do you believe is the most important skill or attribute of a successful founder?
Andrei: Being naïve enough to believe you can do it, yet curious enough to close your gaps before doubts catch up. Also Grit + perseverance.
Lisa: Hard to pick one. I believe one of the most important skills for a successful founder is adaptability. Things rarely go as planned, and being able to pivot, learn quickly, and make decisions in the face of uncertainty is critical. It’s not just about resilience—it’s about staying curious, open to feedback, and willing to challenge your own assumptions. Adaptability allows you to navigate setbacks, seize opportunities, and keep growing alongside your business.
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