JSON Startups

Fabrizio Rinaldi and Francesco quit their tech jobs in late 2018 to launch side-projects under Superlinear. They built Mailbrew, a SaaS app that creates automated email digests from users' favorite sources (Twitter, Reddit, blogs, RSS feeds), launching in March 2020 after a 6-month private beta. Within weeks of launch, they had 2,000+ signups, made it to the front page of Hacker News, acquired 40 paying customers, and reached $2,000/month MRR.

Crave Cookie is a hyper-local cookie delivery business founded by Sam Eaton and his sister in 2018. Starting from their mother's kitchen with a cottage food license, they built a custom software platform that optimized order management, delivery logistics, and customer experience. By focusing on quality (always-warm cookies), handwritten gift messages, and organic word-of-mouth growth, they scaled to $200k+ monthly revenue with 35-40% margins and 60% customer repeat rate, eventually expanding to multiple delivery hubs.

Handshake, a 10-year-old career marketplace with 18M students and professionals, launched a data labeling business in January 2024 by leveraging its massive network of experts (500k PhDs, 3M master students) to create high-quality training data for frontier AI labs. In just 4 months, the new business hit $50M in revenue; by 8 months they're on pace to exceed $100M ARR—rivaling their core business in annual revenue.