Decoding a Viral Indie Hacker’s Mindset

When 29-year-old Samuel Rizzon is asked what he does for a living, he offers a single word: “developer.” It is technically accurate, but it barely scratches the surface of a career that has spanned enterprise software, open-source contributions, and viral consumer products. At an age when most engineers are still narrowing their focus, Rizzon has refused to be pinned down to just one thing.

His trajectory began early. Fascinated by technology from childhood, he shipped his first product at 19: a Bible quiz app for the Play Store and App Store in 2015. It racked up 22,000 downloads, and that response convinced him that building things people actually used was a path worth pursuing. Soon after, he joined TOTVS, Brazil’s largest tech company, where he would spend five formative years.

The foundation of his career took shape around a single product. It started as a proof of concept for a client that needed a way to sign documents digitally. Rizzon wrote the entire thing from scratch, and the prototype worked so well that it became a standalone product. What emerged was an electronic signature platform comparable to DocuSign, now processing over a billion documents for more than a million customers. He built it largely alone, before AI coding assistants existed, architecting the full stack himself: an Angular front end, a C# back end, a Chrome extension, and a desktop app that reverse-engineered the physical A1 and A3 devices Brazilians use for document authentication. As the product matured, a team of roughly 10 engineers, designers, and product staff formed around him, with Rizzon leading the transformation from prototype to full product line.

After five years at TOTVS, he spent a year at the consultancy CI&T, then took a remote role as a full-stack engineer for a New York startup. That job gave him his first direct exposure to the U. S. tech scene.

Around the same time, Rizzon decided to build a company of his own. He ran it out of his bedroom in Brazil, with no investors, no team, and no network. What he had was sheer persistence. He took the business from zero to 30 paying customers across Brazil, the United States, and Ireland, with 8,000 people using its web app. Since there was no one else, he handled sales, client conversations, support, and marketing himself , the parts of a business most engineers never touch. He even started a YouTube channel that grew to 3,000 subscribers.

He does not romanticize the struggle. “I had nothing, really nothing,” he says. “It was just me in my room. Creating something and trying to sell it and reach customers. It was a very specific niche, and it was a hard niche.” That isolation forced him to operate entirely on his own, and the founder instincts it forged would later resurface in the viral consumer projects that made his name.

During the 2020 pandemic, when work and school shifted to video calls, Rizzon built a Chrome extension that muted every participant on a Google Meet with a single click. It solved a problem he kept running into himself. Within a year, the extension reached 150,000 users, almost entirely through word of mouth. Its most devoted users were teachers, who ran online classes for 15 to 30 students and had no way to quiet the room without clicking each child individually. “It was a pain for me, and I just fixed that with an extension,” Rizzon says. “It ended up being useful for a lot of teachers in particular.”

The traction caught the attention of the founder of MP3.com, who emailed Rizzon with an offer to buy it. He sold, marking his first exit and an early sign of the instinct for shipping consumer products that would shape his later work. He has stayed close to open source since, serving as co-founder and core component developer of Zard UI, a shadcn-style component library for Angular developers that has crossed 1,000 stars on GitHub.

The project that finally broke through was GitCity. The idea came from a post on X about rendering a city, and Rizzon had a first version live within a day. He built the entire codebase with Claude Code, writing nothing by hand. What it produced was a pixel-art 3D metropolis that renders GitHub developers as buildings, one structure per coder. “On the first day, when I had the idea of creating the city, I noticed that this could be a viral product,” he says. “So I prepared and made everything to go viral.”

People took to it immediately. In its first week, the city grew from 12,000 buildings to 40,000, and it currently holds more than 80,000. Over two months, GitCity drew 180,000 visitors, more than five million social media views, and 5,000 GitHub stars, with roughly 20 people contributing code. Rizzon’s own audience grew alongside it, climbing from 200 Instagram followers to 6,000 and an X account to nearly 4,000.

None of that happened by chance. Rizzon treated distribution as part of the product itself, wiring a one-click “share on X” button into every user action. He added a feature that lets one building attack another, which fires off an email to the target and pulls them back in to retaliate. He opened the experience with a cinematic shot of the skyline and made the 3D rendering run smoothly on phones. Inspired in part by indie developer Pieter Levels, he has also begun earning money from it, taking in $2,000 from sponsored buildings and lining up companies to back a week-long event where users hunt down a “dark boss” hidden in the city.

The project did more than rack up numbers. It brought recruiters from Delphi, who were looking for someone to carry that same obsession with user experience into their consumer product. Rizzon is now joining as a product engineer on their San Francisco team. He treats the move less as a destination than as a long apprenticeship, a chance to build a network and learn how the U. S. startup world actually works before starting a company of his own.

Whether the right title is developer, founder, or product engineer, Samuel Rizzon has spent a decade declining to choose just one. The same engineer who built a signature platform now handling more than a billion documents at TOTVS also turned GitCity into a viral calling card. It is proof that the instinct to ship and the obsession with how a product feels follow him regardless of the label.