This week on the First Round Review, we're back with another installment in our Paths to PMF series, this time with Replit's CEO and co-founder Amjad Masad.
Replit’s Path to Product-Market Fit—The $1 Billion Side Project
The startup world loves its archetypes—the wunderkind entrepreneurs who've been dreaming up business ideas since their lemonade stand days.
But Amjad Masad’s journey to building Replit began not with dreams of entrepreneurship, but with a singular vision: to democratize the power of software development. Leading a business was more of a means to an end.
In 2008, as a CS student in Jordan charting his path to Silicon Valley, Masad was unknowingly laying the groundwork for a billion-dollar business. His "mad science experiment," Repl.it, started as a simple solution to a frustrating problem: the inability to collaborate on code in real-time in the browser. He assumed this task would prove to be difficult, since no one had done it before.
"It turns out, the prototype was easy," Masad says. "I created a text box where you could input JavaScript, click a button, and it would evaluate the code. There was also a way to save and share it, and I immediately got feedback that what I was building was useful, which is what every developer wants to hear."
But despite these early signals of product-market fit, Masad shelved it. He more or less abandoned the IDE project he started, and went on to pursue a career as a software engineer, making pitstops as the founding engineer at Codecademy and starting the JavaScript infrastructure team at Facebook.
Even without Masad's active involvement, Repl.it continued to gain traction. "Even though Replit by this point had been abandoned and parts of it were broken, developers still kept coming back to use the product because there was nothing else out there," Masad says. By 2016, it had amassed over 100,000 users, mostly students and self-taught programmers who discovered it through word of mouth (pretty impressive for a project put on ice!)
To Masad, the pathway to fulfilling his vision of equal access to software creation had crystallized. Which meant it was time to take a real crack at building a business.
Fast forward to 2024, and that experiment has evolved into Replit, a $1B company with 30 million users and over $200M in funding.
In the latest installment of our Paths to Product-Market Fit series, Masad takes us on Replit's unconventional journey from college side project to billion-dollar AI startup. His story is stuffed full of unique insights and founder lessons — here’s a sneak peek at three of them:
- Don't be afraid to go broad when others go narrow: "I decided to place a bet on becoming a general purpose platform,” Masad says (a gutsy call when most were going all-in on JavaScript). “I thought we shouldn't be in the business of betting on certain languages, rather, we should support as many languages as we can.” This became the secret lever they pulled to scale ahead of the competition.
- Invest early in emerging technologies: Just last month, Replit rolled out Replit Agent, its agentic code-writing assistant tool, that lets users create live applications from just a few lines of text. But Masad laid the groundwork for that innovation long before trying to build anything for customers. "It wasn't until GPT-2 that we started actually writing code and experimenting with it,” Masad says. “But understanding the machine learning stack was so hard and the training was still inaccessible so, while we had some experiments that were exciting, we never shipped anything."
- Focus on experimentation over immediate commercialization: "My advice for founders entering the space: Think about all the cool projects there are to do and give yourself enough time — especially if you're still in school — to pursue that,” he says. “Don't start with the intent of starting a company or commercializing. Instead, ask yourself: what is something really interesting and cool that I can do with this technology?"
Thanks, as always, for reading and sharing.
-The Review Editors
Recommended resources:
-This essay on the importance of data when making decisions in the engineering industry
-The best way to test Web APIs
-5 tips for planning your career like a product from Ami Vora