Avoiding becoming a founder at all costs

As a kid, Zeno spent Sundays helping his dad sell handmade superhero costumes at their local market in Brazil. Without a storefront, the family relied on that one day to bring in all the sales they could make. They spent the week sewing and stayed up late Saturday to prep, but if it rained the next day and fewer people showed up, they might not have enough money for groceries. That kind of pressure, watching your family’s stability hinge on uncontrollable factors like weather, leaves a mark.

Zeno didn’t see freedom in entrepreneurship. He saw pressure and uncertainty. Early on, he made a promise to himself to get a stable job, avoid volatility, and keep things safe.

But he couldn’t shake the urge to build. Even while working full-time as a developer, he always had a side project going. One of those was Dracula, a dark UI theme that launched in 2013 and eventually pulled in more than $400K in revenue. Still, he had no intention of becoming a founder.

“I never put CEO in my title or on LinkedIn. I didn’t feel like I was an entrepreneur. That word scared me.”

He spun up companies, hired contractors, and shipped products, but told himself it was all just projects. Not a startup. Not becoming a founder. He was just doing what he loved. “I always had this side of me that just wanted to build and ship things,” Zeno says, looking back on those early days.

A partnership built on transparency

By the time Zeno joined WorkOS as VP of DX in the summer of 2021, he had the stability, good salary, and a clear path forward he had always wanted. But even in that comfort, he kept building. He was always playing around with new ideas, experimenting with tools, and launching small projects for fun. As long as he stayed that course, he could have everything he wanted without becoming a founder, he thought.

Then Bu, an engineer on Zeno’s team, caught his attention. On paper, Bu looked like any other talented developer who could spend hours deep in code. But what stood out to Zeno was the way Bu showed up.

During a standup, Bu admitted he’d gotten distracted the day before and hadn’t been very productive. But he already had a plan to make that day better. Zeno says, “He’s not afraid of being vulnerable, and that truly inspired me. I remember thinking, ‘That’s a really cool trait to have in a cofounder.’ It created a level of trust.”

In a world where most people want to look like a 10x engineer, Bu was refreshingly honest. Zeno saw it as a signal of unusual strength. “I want to distance myself from people with very high egos. And he was the opposite.”

Bu wasn’t new to side projects either. He had launched open-source tools like Taskr, a minimalist task manager that hit #1 on Product Hunt. He immediately clicked with Zeno, someone who loved building just as much as he did, and the two started brainstorming what they could work on together.

The aha moment that launched Resend

Zeno had always admired businesses that solved boring but painful problems. WorkOS had done it with SSO, and Stripe had done it with payments. Zeno and Bu started thinking about another foundational system, email. “Email is extremely boring,” Zeno says. “It’s been around for 20 years, and it will still be here long after Resend. No one wants to deal with it. So I thought, this is a really boring business, and I’ll take it.”

They knew the pain was real since they had both lived it, and every developer they talked to felt the same frustration. Email took forever to set up and maintain. You had to juggle outdated APIs, clunky deliverability settings, and poorly documented tools just to send a basic email. Zeno and Bu’s initial goal was to make email infrastructure feel modern and seamless. Something developers could plug in and trust.

Once they had a working prototype, Zeno shared it with a friend, who immediately wanted to use it for his startup. But Zeno was hesitant. “Dude, you shouldn’t do this in production,” he warned him. “There’s no bug monitoring. The status page isn’t even properly maintained. It’s just me and Bu hacking this together.”

But the friend said it was already better than what he was currently using. So Zeno, thinking he was calling his friend’s bluff, sent him a $10 invoice. His friend paid immediately and started using the product Zeno and Bu were calling Resend.

“That was the aha moment,” Zeno says. If someone else saw value in this, even in its raw state, and was willing to pay, maybe there were others. Maybe this fun side project was becoming something bigger.

They decided to apply to YC because one person saying yes was enough to make them wonder how many more were out there waiting for the same solution.

The leap he thought he’d never take

As the possibility of being accepted to YC became more serious, Zeno found himself overwhelmed by an anxiety he couldn’t quite explain. It wasn’t leaving his stable, high-paying VP role at WorkOS that scared him, it was something else. When he sat down with his wife to talk through his trepidation around joining YC, she helped him see it for what it was, an irrational fear shaped by his childhood, not his current reality. His dad sold costumes locally, relying on a single Sunday market each week, where weather and foot traffic were always uncertain. Zeno could build software once and sell it globally, around the clock, with zero dependency on timing, location, or circumstance. “I had to deconstruct the business model to unblock myself because I was super afraid of taking the leap and quitting my job. My dad was limited. I can sell globally, 24/7. That helped me remove the fear.”

Getting the yes from YC was exhilarating. Most founders accept immediately, but for Zeno, it wasn’t that simple. He never saw a path that led to him becoming a founder. He had to stop and think. He knew that if he accepted the invitation, everything would change. He’d have to quit his job, possibly uproot his wife and 1-year-old daughter, and figure out how to keep supporting his parents. He had a long conversation with Bu, and they decided they were all in. “I remember the first two days after, I slept two or three hours tops. My brain was outside of my body. My wife told me, ‘I thought you were going to die.’” It was the highest emotional peak he’d felt since starting to work on Resend.

He knew that leaving the safety of WorkOS raised the stakes. Resend had to work. There was no backup plan. But that pressure became fuel, and it marked the beginning of Zeno stepping fully into the role he had spent years circling.

The missing piece of the founding team

When Zeno and Bu began their YC batch, they realized they were missing a crucial piece of the foundational team. They needed someone who could run operations with the same focus and care they brought to product and engineering. Email is a sensitive category. As Zeno says, “It’s an industry known for phishing. We knew we were going to need help.”

When he raised the idea with their YC partners, the response was blunt. “That’s a big mistake. You shouldn’t be hiring anyone right now. Why do you need operations if you don’t even have a launched product?” In their view, founders in the middle of a batch should focus on two things: talking to users and building product.

What they didn’t know was that Zeno already had someone in mind who had earned his trust over years of working together. When leading product at Liferay Cloud, the founder urged Zeno to interview a guy named Jonni for a developer advocate role, despite his lack of a technical background. “Trust me,” the founder said, “This guy is your Robin.” Zeno was skeptical, but as soon as they spoke, he saw why the founder was so insistent. “Jonni was really special in the sense of being smart, but super humble and willing to learn.” His zero-ego presence reminded Zeno of what he’d first recognized in Bu.

Zeno hired Jonni at Liferay, where he quickly proved he could take on anything. He jumped from developer advocacy to product to ops, even leading the charge on SOC2 compliance. “Whatever problem you threw at him, he’d figure it out. He’s not an engineer by training, but he is one of the best problem solvers I know,” Zeno says. “He also brought this inspiring energy to the room. He motivated people, anchored the culture.”

Zeno went with his gut and brought Jonni on as a co-founder at Resend even though he’d been advised not to. Looking back two years later, he sees it as one of the best decisions he’s made. “I trust him 10,000%. I knew he’d be a pillar at Resend.”

YC mindset and consistent execution

With the founding team in place, Resend was dialed in. A few weeks after starting YC’s W23 batch, Resend already had 6K signups on the waitlist. The early interest was encouraging, but they didn’t want to coast on it. “We don’t want to be the 30th best company or the 70th or the 3rd. We want to be the 1st,” Zeno says, remembering the mindset he and Bu set going into their batch. They held themselves to a higher standard, focusing on every detail and pushing to ship products that felt fast, reliable, and genuinely delightful.

In the months following YC, Zeno, Bu, and Jonni gradually let in users from the waitlist so they could learn from real feedback and iterate fast. By June 2023, they were confident enough to remove the waitlist and make Resend publicly available. What happened next is every founder’s hope: new users kept signing up steadily and consistently. It wasn’t a spike followed by a drop-off. Something was working, and it was sticking. A few months later, they hit 20,000 users. Within a year, that number grew to over 100,000.

The night they thought it was game over

Every startup has moments that test what it’s made of. For Resend, one of the lowest came late one night during a routine migration. Zeno got a text from Bu around 9 p.m. “Get to your computer and get on a call right now. The database is empty. We deleted everything by mistake.”

Zeno’s heart sank when he saw that everything was gone, but he hoped they could recover it quickly. After five hours of waiting, they saw that nothing had been recovered, only to realize they’d worked off of the wrong backup. They’d used the one created after the deletion. They started over, working through the night. “That was the worst day ever,” Zeno says. “I thought people would never trust us anymore. It was terrible. I still have that scar in my body.”

By the time the system was fully back online, Resend had been down for nearly nine hours, and customers were pissed. Cancellations started coming in. Zeno thought Resend was done. “I felt like, yeah, this is it. This is over. It was good while it lasted, but now it’s gone.”

But he, Bu, and Jonni didn’t quit, and the customers who saw the value in Resend stuck around. The co-founders rebuilt their security practices, controls, and backup systems. “I’m actually very grateful that it happened early in the life of the company,” Zeno says, “Because that meant we could recover with a better product later.”

Quality as a differentiator

Resend entered a category filled with deeply entrenched players. Competing with them by being louder or cheaper wasn’t going to cut it. Zeno, Bu, and Jonni knew they had to stand out by building something that felt instantly and undeniably different, starting with the moment someone landed on the site.

They put quality at the center of everything. The product had to be simple, fast, and reliable. The interface had to be clear. The entire experience had to feel polished in a way that developers could immediately sense. Those values were already deeply embedded in how Zeno had built Dracula, and the same principles carried over, that every detail mattered.

Since day one, Resend’s landing page has featured a Rubik’s Cube rendered in 3D. It represents the level of attention to detail, polish, and care that Resend stands for. Building something like this would push even experienced designers, let alone an engineer coding it from scratch. Zeno and Bu stressed over the details, fine-tuning everything from the lighting to the texture to make it feel real. For Zeno, the cube was a way to show what words couldn’t. “We could say we care about quality, or we could demonstrate it. Our whole distribution strategy has been centered around the fact that we’re different. People notice when someone does something a little better or clearly cares about the details.”

They didn’t talk about product quality as a differentiator, let alone shout it. They let the product prove it. That consistency helped them grow steadily, from an idea with a waitlist to a company trusted by thousands of developers.

Today, Resend has passed 10K paying customers, 600K users, and over 1B emails sent. But in Zeno's eyes, there’s much more to do. “We’ve seen movements that give us more confidence to say, maybe we achieved PMF. But even today, I have a hard time saying that out loud.”

Becoming the founder he never planned to be

Zeno once resisted the title of founder. Now, he wears it without hesitation. The fear that kept him on the sidelines has been replaced by confidence and conviction. “It feels insane to go back to that path I was on before,” he says. “If everything goes down and Resend is no longer here, it’s fine. I’ll do another company.”

Resend has become something Zeno never let himself imagine in the early days. The pressure he saw his dad carry all those years didn’t stop him from becoming a founder, it shaped him. It made him more careful, more motivated, and more prepared to build something that could last. Today, Zeno is creating the kind of company that would have made that little boy at the market stall believe a different future was possible.