When 29-year-old Samuel Rizzon is asked what he does for a living, he answers with one word: “Developer.” While accurate, it’s a humble label for someone whose work extends far beyond writing code.
In an age when many engineers still settle into a single specialty, Rizzon has built three arenas that rarely reward the same instincts: large enterprises, online classrooms, and products embraced by the open source community. His versatility is the story of an engineer who never wanted to be just one thing.
From bedroom software to billions of documents
Interested in technology and building software from a young age, Rizzon developed and shipped his first product at the age of 19: a Bible quiz that he published on the Play Store and App Store in 2015. He got 22,000 downloads, and that response was enough to convince him that creating things that people actually use is worth pursuing. Not long after, he joined TOTVS. Brazil’s largest technology companyhe will spend the next five years here and lay the foundation of his career.
This foundation was formed around a product. It started as a proof of concept for a client who wanted a way to digitally sign documents. Rizzon wrote it from scratch and the prototype worked well enough to become a product in its own right. It has grown into an independent e-signature platform comparable to DocuSign and today processes more than a billion documents for more than a million customers.
Its construction was largely a solitary effort. Working before AI coding assistants existed, Rizzon architected the entire stack himself, from the Angular frontend and C# backend to the Chrome extension and desktop software that reverse-engineered the physical A1 and A3 devices Brazilians use to authenticate documents. As the product matured, a team formed around it, eventually growing to about 10 engineers, designers and product staff, with Rizzon leading the work that turned the prototype into a full product line.
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From there, he spent a year at the CI&T consulting company and began working remotely as a full-time engineer at a New York startup.
Gain experience as a founder
Around the same time, Rizzon started to build his own company. ran away from his room in Brazil, without investors, without a team and without a network to rely on. What he did have was persistence, and it showed: he took the business from nothing to 30 paying customers, 8,000 people across Brazil, the US and Ireland using the web app.
With no one else to do it, he handled sales, customer negotiations, support and marketing himself, parts of the business that most engineers never touch. Even during this time, he started a YouTube channel that reached 3000 subscribers.
He doesn’t romanticize how hard it is, and he’s particularly candid about the difficulty of doing it from Brazil, far from any real startup network. “I had nothing, I had nothing,” he said. “It was just me in the room. I was creating something and trying to sell it and reach customers. It was a very specific place and it was a difficult place.” This isolation forced him to strike out on his own, and his founding instincts would resurface in the viral consumer projects that would later make his name.
A one-click fix found by 150,000 users
In the 2020 COVID-19 pandemic, when work and school suddenly took place over video, Rizzon built a Chrome extension that mutes every participant in Google Meet with one click. The fix was simple, but it turned out that many other people had the same complaint.
This became clear quickly. Within a year, the extension reached 150,000 users. almost all of it comes from word of mouth. Its most loyal users were teachers who held online classes for 15-30 students and couldn’t quiet the room without clicking each child one at a time. “It was a pain for me, and I just fixed it with an extension,” Rizzon says. “It’s been especially helpful for a lot of teachers.”
The traction caught the attention of MP3.com’s founder, who emailed Rizzon with an offer to buy it. He sold his debut, marking an early sign of the instinct to ship consumer products that would shape his later work. He has been close to open source since his time as co-founder and lead component developer of Zard UI, a shadcn-style component library for Angular developers that has passed 1,000 stars on GitHub.
A city designed by him to go viral
After years of projects being shipped one after the other, it finally broke GitCity. The idea came from a post about rendering a city in X, and Rizzon went live with the first version within a day. He wrote none of these by hand; instead of built the entire code base with Claude Code. What he produced was a pixel-art 3D metropolis that presented GitHub developers as a building with a structure to each coder.
“The first day I had the idea to create the city, I saw that it could be a viral product,” he says. “So I prepared and did everything to go viral.”
People immediately accepted it. The city grew from 12,000 buildings to 40,000 in the first week and now has over 80,000 buildings. In two months, GitCity attracted 180,000 visitors, more than five million social media views and 5,000 GitHub stars, with about 20 people contributing code. Rizzo’s own audience has grown with him, growing from 200 Instagram followers to 6,000, and his X account has nearly 4,000.
None of this happened by accident. Rizzon the distribution is treated as part of the productintegrate a one-click “Share on X” button to every action a user can take. It also added a feature that allows one building to attack another, sending an email to the target and pulling them back to respond, and it also opened up the experience with a cinematic silhouette shot and made 3D rendering run smoothly on phones.
Partly inspired by indie developer Pieter Levels, he also began monetizing it, taking $2,000 from sponsored buildings and lining up companies to support a week-long event where users hunt for a “dark boss” hidden around town.
The project did more than collect numbers; he brought in recruits from Delphi, who were looking for someone to bring that same obsession with user experience to consumer products, and he now joins the San Francisco team as a product engineer. He sees the move as more of a goal than a long apprenticeship, more a chance to network and learn how the US startup world really works before starting his own company.
More than a developer
Whether the right title is developer, founder or product engineer, Samuel Rizzon refused to choose just one for ten years. The same engineer who built a signature platform that now manages more than a billion documents at TOTVS turned GitCity into a viral calling card, proving that an instinct to ship a product and an obsession with how a product feels follows it, regardless of label.
