I take professionalism to mean you know your craft. Like for example setting the TTL on a DNS server to a year won't cause downstream services to cache the record for a year but instead something on the order of a few hours to a few days in practice.

To quote RFC 2181: "Implementations are always free to place an upper bound on any TTL received, and treat any larger values as if they were that upper bound. The TTL specifies a maximum time to live, not a mandatory time to live."