What a job it is to make the conversions? (7)
I believe the answer is:
mission
'what a job' is the definition.
(a mission is a job or task)
'it is to make the conversions?' is the wordplay.
I cannot quite see how this works, but
'is' is within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for mission that I've seen before include "Journey with a specific purpose" , "Delegation" , "Vocation; embassy" , "Ministry sent by a church to spread its teaching" , "Very dangerous assignment -- Tom Cruise film series" .)