How we prevent conflicts in authoritative DNS configuration using formal verification

Cloudflare has implemented a formal verification system called Topaz to ensure the correctness of its internal DNS addressing behavior. The system uses a custom Lisp-like programming language and runs in production, checking for bugs before programs are deployed. Topaz is part of a larger addressing system and helps make the internet more reliable by providing an example of formal verification applied to networked systems. It also allows Cloudflare engineers to write certain programs that absolutely cannot overlap with other programs, ensuring their consistency and reliability.