Sonny Li

Sonny Li is a Brooklyn-based educator and founder best known for Codédex, a learn-to-code platform styled like a retro role-playing game, in which learners travel through regions for Python, HTML, CSS, JavaScript and more, earning XP and badges. Codédex passed 2 million users and $1 million in annual recurring revenue in 2026, and shows about $82,000 in verified monthly revenue on TrustMRR.

Li grew up in Shanghai and moved around Germany, France and the United States (Oregon, Ohio and New York) because of parents working in academia. After a computer science degree, Li came to New York for a PhD program, left it, and turned to teaching: C at Columbia University, data structures and algorithms in Python at NYU Tandon and Java at Lehman College. Li then spent close to five years at Codecademy as a curriculum developer, writing many of its programming courses, before the company was sold to Skillsoft for $525 million.

In 2022 Li quit Codecademy to build Codédex as a solo founder, with the pitch of making coding education fun for Gen Z by borrowing from the games and nostalgia that drew many people to programming in the first place; the name is a nod to the Pokédex. The platform launched on Product Hunt in November 2022 and grew through Li's own Python and startup content and a community of learners in more than 170 countries. Revenue comes mainly from Club, a paid membership that unlocks advanced courses, projects, challenge packs and the AI tutor Lumi.

Li has written openly about four years spent in survival mode before Codédex turned consistently profitable in 2026. Recent releases include Codédex Builds, an in-browser environment for multi-file projects with live previews and public URLs, learning journeys covering web development, data science, AI, game development and design, and an annual community game jam.

Li is part of a small group of indie founders competing with venture-funded coding schools, using a tiny team, a strong visual identity and a highly engaged community.