FYI
Those contemplating these positions should be aware of the following.
For those who are not an Australian citizen (or Australian Permanent Resident), the legal basis for a foreign national being able to work in Australia is a 457 visa. This is a temporary work visa which does not confer permanent Australian residency.
Additionally, the visa is position, type and company specific. Should a person change position or type within the sponsor company the visa is subject to cancellation. Also, if a person should leave the sponsor company for any reason the visa is subject to cancellation.
A person who does not hold a valid visa to be in Australia, or whose visa has been cancelled, must leave Australia or be subject to deportation.