Need Interview Questions & what should be qualification to be asked while hiring a Developer

Hi experts

we are planning to hire a SAP Business One Developer, to our company,, as our company has lot of Requirement which cannot be met by Functional level person.

so i request all the participant i this forum those who knows

1.What should be the qualification required for a Developer and year of experiance

2. What questions should we ask when we hire an experience Developer

pls list out the question 1,2,3...... wise

Regards