Case Study on Approximated.app - A Web App Domain Automation Tool Built with Elixir

Carter, who has been a long-time member of the Elixir community, detailed the journey and architecture of Approximated.app, a web application designed to automate custom domains at scale using the Elixir/Phoenix stack. Approximated.app assists various types of web applications like blog hosts, SAAS platforms, and marketplaces by seamlessly managing their custom domains. The service currently supports over 200k custom domains, manages proxy clusters globally, and handles millions of requests daily, all powered by Elixir and related technologies like Oban for queueing and LiveView for UI interactions. The application maintains high availability with 99.87% uptime and surprisingly, all these operations are managed by a single developer. Carter overcame early challenges, such as bugs that caused high CPU usage without affecting users due to the robust process scheduling of the BEAM. The backend stack is supported by a Digital Ocean managed Postgres instance and Fly.io for distributed operations. Carter's work exemplifies the utility and scalability of Elixir in production environments for solo developers.