A DevOps engineer supporting Meta infrastructure needs to explain DNS clearly, including what it does, how a lookup works, and why it matters for reliability and security.
Assume a user opens www.facebook.com from a browser. Explain what DNS does and walk through the request path from the client to the final IP address. Your answer should be practical, not purely academic.
If a laptop inside Meta’s corporate network tries to reach www.facebook.com, what role does DNS play before any TCP or TLS connection is established?
A strong answer should show that DNS is a distributed naming system that maps human-readable names to machine-usable records, not just “a phonebook for the internet.” It should also connect DNS to real infrastructure concerns: caching, latency, redundancy, and security controls such as DNSSEC or resolver hardening.