It's not a hyperbole because we're not exaggerating, it's not alliteration because the letters are not repeating, it's not personification because you are not giving a non living thing human characteristics.
It is not a simile because you're not using like or as, it's not a metaphor, it's not an onomatopoeia, or sensory imagery.
Explanation: A metaphor is a figure of speech in which something is compared to something else by stating that they are equal. In this case, "was" equates the interview to a piece of cake, making it a metaphor.
