I was looking at the description of this role i.e. someone who provides cruise flight relief flying. As conceivably, someone could be bonded for multiple years because of the type rating being covered by the airline, it is possible they could 'fly' for multiple years and yet never actually do a real takeoff or landing?
The short answer is: yes
Personal Licensing regulation outlined in Annex 1, 2.1.4 "Circumstances in which class and type ratings are required" states that:
220.127.116.11 A Contracting State having issued a pilot licence shall not permit the holder of such licence to act either as pilot-in-command or as co-pilot of an aeroplane, an airship, a helicopter or a powered-lift unless the holder has received authorization as follows:
a) the appropriate class rating specified in 18.104.22.168; or
b) a type rating when required in accordance with the provisions of 22.214.171.124.
126.96.36.199.1 When a type rating is issued limiting the privileges to act as co- pilot, or limiting the privileges to act as pilot only during the cruise phase of the flight, such limitation shall be endorsed on the rating.
ICAO - Annex 1 - Personnnel Licensing
Though vague about takeoff, landings, or other stages of flight, this published regulation is clear that
- Cruise pilots acting only during cruise phases of flight is allowed, providing they have the appropriate class or type rating
- The limitation of their role, such as cruise flight only, is endorsed on the respective rating.
Your question didn't ask about what state/country you were asking about