In an era dominated by “vibe coding,” Zach Yadegari, the 18-year-old founder of Cal AI, presents a refreshingly old-school contrast.

The irony lies in the fact that Yadegari and his co-founder, Henry Langmack, are both teenagers who have recently graduated from high school, yet their story is a classic tale of entrepreneurial success.

Since its launch in May, Cal AI has reportedly generated over 5 million downloads in just eight months, according to Yadegari. Moreover, he claims that the app has achieved a customer retention rate of over 30% and generated $2 million in revenue last month.

Although TechCrunch was unable to verify these claims, Cal AI boasts an impressive 4.8-star rating on the Apple App Store, with over 66,000 reviews, and has surpassed 1 million downloads on Google Play with a 4.8-star rating based on nearly 75,000 reviews.

The concept behind Cal AI is straightforward: users take a picture of their food, and the app logs the calories and macros for them.

While this idea is not unique, with established players like MyFitnessPal and SnapCalorie offering similar features, Cal AI’s advantage lies in its utilization of large image models from Anthropic, OpenAI, and RAG to improve accuracy, trained on open-source food calorie and image databases from sites like GitHub.

“We’ve found that different models perform better with different types of food,” Yadegari explains to TechCrunch.

Throughout the development process, the founders overcame technical challenges, such as recognizing ingredients from food packages or in complex dishes.

The result is an app that its creators claim is 90% accurate, which appears to be sufficient for many users tracking their diets.

Teen coders and a hacker house

Yadegari’s early success has also brought him some fame, but unlike many teen coders who grew up with AI-powered tools, he began mastering Python and C# in middle school.

In the ninth grade, Yadegari built his first business and sold it for $100,000 to FreezeNova when he was 16.

The idea for the business came about when schools started giving out Chromebooks to students, who would then try to play games on them during school hours.

Yadegari saw an opportunity and created a website that provided access to unblocked games, cleverly naming it “Totally Science” to avoid being blocked by the school.

After selling his first business, Yadegari and Langmack watched Y Combinator videos and connected with other coders on X, where they met Blake Anderson, who became a co-founder of Cal AI.

Anderson, now 24, had already gained recognition for creating consumer apps like RizzGPT and Umax, which offered ChatGPT-powered dating advice.

The idea for Cal AI was born when Yadegari started going to the gym to gain weight and “impress girls,” he admits with a smile.

The founders then made the quintessential decision to move to San Francisco and live in a hacker house while building their prototype.

However, during his time in the hacker house, Yadegari, whose parents are both lawyers, learned a valuable lesson that went against the typical Silicon Valley dropout narrative.

“It was a fun experience, but I realized that if I didn’t go to college, this is what my life would be like,” he reflects.

While Yadegari has not yet decided which university he will attend, he and Langmack are enjoying the experience of running their company, which now includes another co-founder, Jake Castillo, and eight full-time employees.