Dear Madam

As I know it is no any restriction for Iranian passport to get working permit , firstly it need to get job from Qatar Airways then the Qatar airways will take care of his residence visa application and it will not big issue but it may take a little long time , maybe one to 2 month depands on sponsor power to move it faster in whole process .
anyhow every government must take care of who is coming to his country.

wish him best luck
go for it and it will be done ,
do not waste time to ask here and there , everything is different from words to reality ,just do it. just please do not trust all those commissioner , make it straightforward with Qatar Airways , all those are commissioner are wasting your time and money and nothing can do ,
first step is get job offer from Qatar airways then leave the rest of it to Qatar Airways , they will do it perfectly .