Eric Simons and Albert Pai, childhood friends from Chicago, founded StackBlitz in 2017 — a browser-based IDE. Eric was a self-taught developer who'd previously co-founded Thinkster (coding education, acquired 2018). They spent four years building WebContainers, a breakthrough technology that runs full Node.js in the browser via WebAssembly — a "tiny Rust kernel" that cold-boots under 10MB.

Seven Years of Infrastructure Work

By 2023, StackBlitz had a technology marvel but almost no revenue — roughly $80K ARR. The company was weeks from shutting down. The board gave them an ultimatum.

The Model That Changed Everything

In February 2024, Eric and Albert prototyped a concept called "Bolt" — AI-powered app generation running entirely in the browser. But the AI models available weren't good enough. They shelved it. Then in June 2024, they got early access to Anthropic's Claude 3.5 Sonnet — the first model capable enough to make the concept work. They committed to building Bolt in July 2024.

One Tweet, $60K ARR on Day One

On October 3, 2024, Eric launched Bolt.new with a single tweet. No marketing budget, no launch campaign. Day one: $60K ARR. Day two: $80K ARR — already matching StackBlitz's total after seven years. The product went truly viral across Twitter, Reddit, YouTube, and TikTok. Creators posted demos of Bolt building full apps in real-time.

Within 4 weeks: $4M ARR. By January 2025: $20M ARR. By March 2025: $40M ARR with over 3 million registered users.

• StackBlitz founded: 2017
• WebContainers development: 4+ years
• Pre-Bolt ARR: ~$80K (nearly shut down)
• Bolt launch: October 3, 2024
• Day 1 ARR: $60K
• $4M ARR: 4 weeks
• $20M ARR: ~3 months
• $40M ARR: ~5 months
• Series B: $105M at $700M valuation (January 2025)