Summary
Buttondown, founded by Justin Duke, is a simple yet effective newsletter software developed as a side project while Duke was an engineer at Stripe. It caters to a diverse range of customers, including niche blogs and startups, and has grown to generate $15K in monthly revenue. Duke built Buttondown to address the gap in the market for a lightweight newsletter tool that integrates seamlessly with personal blogs, focusing on performance, Markdown support, and a minimalist interface.