AWS Route 53

Amazon Route 53 is AWS's Domain Name System service, combining authoritative DNS on globally dispersed servers with domain name registration and health checking. It provides visual traffic flow tools for configuring routing, automatic scaling with load, and customisable routing policies for latency, availability and compliance.

Routing policies are what distinguish this from a records-and-nothing-else DNS service. Latency based routing sends a user to whichever region answers fastest for them, weighted routing splits traffic for a gradual release, and failover routing moves traffic away from a region that stops responding. Those are deployment and resilience mechanisms that happen to be implemented in DNS.

Health checking is the part that makes failover meaningful. DNS on its own has no notion of whether the address it returns still works, so a record pointing at a dead endpoint keeps being served until a person changes it. Checking endpoints and withdrawing failed ones automates the response at the layer every request passes through.

Bundling domain registration matters mainly for coherence. Registrar, DNS and the infrastructure behind it in one account removes the delegation mistakes that cause a surprising share of outages, usually at renewal, when nobody notices the domain has lapsed until it stops resolving.