Yes, the Duomo di Sant' Andrea is a mish-mash of architectural elements but you can detect a lot of Arab-Norman looks in this Duomo.
The Duomo is reached by 62 steps from the main piazza of Amalfi. The inexpensive tour of the Duomo starts at the 11th century Chiostro del Paradiso (Cloister of Paradise) and continues into the 9th century basilica where you'll see a museum containing treasures from the cathedral complex.
From there you'll be taken down to the crypt of St Andrew from the 13th century, where the saint's remains are kept.
Finally, you'll arrive at the Duomo itself, an 18th century baroque restoration.
Following along with our pictures, you'll see glimpses of all these elements of the cathedral complex.