Almost never - you will not be required to attend an interview under most circumstances. Under rare circumstances the embassy may ask for an interview. However, this is the exception, not the rule.

In most cases, these are the only documents you will require. The embassy reserves the right to ask for extra documents depending on the individual applicant’s circumstance.

If you will be travelling with a retired or minor person, you must carry proof of their retirement (for retired persons) / birth certificate (for minors). If they are travelling alone, you will need the same documents. A minor travelling alone needs to have a letter by their legal guardians that states that the guardians are fine with the minors travelling alone.

Generally the validity of the visa is 90 days, however, you can only stay in Egypt for a maximum of 30 days at a time in one single visit.