This might clear a few things up:
"To facilitate an exciting period of growth, Tigerair has a number of contract opportunities for Boeing B737 First Officers in our Melbourne base and Airbus A320 First Officers to join the team in our Brisbane, Melbourne and Sydney bases. Contracts will be for a minimum term of (18) months. At the completion of the contract, it may be possible to gain permanent employment with Tigerair. The endorsement will be provided by Tigerair if required, but is subject to a return of service agreement. Preference will be given to First Officers who already hold a current type rating."
From:
https://tigerair.com.au/corporate/careers