We went through this recently at Codeship when our provider, DNSimple, had an outage due to DDoS- https://blog.codeship.com/dnsimple-ddos-outage/
DNS is a service that often ends up as a single point of failure in infrastructures I've seen as it's non-trivial to implement redundancy. Having a repository/API approach to deploying DNS records saved us in this incident: http://blog.codeship.com/dnsimple-dns-history-continuous-dep...