How a Product Designer Built a Service with 280,000 DAU on Their Own

Product designer Go Seojin built “Online Damta,” a service that moved smokers’ break-time culture online, and shared it on LinkedIn to strong attention.

The product quickly reached 800 concurrent users and 280,000 DAU, then continued operating through server migration and feature updates.

He handled planning, building, and operations largely alone using AI tools and vibe coding, showing how a single designer can ship and scale a service.

The case highlights how AI is changing product development workflows and expanding the scope of a designer’s role.