Zeus: very dominant personality (king), intelligent (see: Metis), bit of a temper, womanizer. I'd say some kind of CEO or bigshot politician.
Hera: also dominant, proud, protector of women/motherhood/marriage, beautiful, gets pretty jealous and wrathful--sufficiently so that Zeus himself gets scared of her temper. I like to think she'd be some kind of political or social activist with strong feminist ties. Think Gloria Steinem.
Poseidon: moody, competitive, easily insulted, likes the sea. I can see him preferring to work with marine animals instead of people and just swimming with dolphins all day. Or wrestling sharks.
Hades: aloof, keeps to himself, minds his own business, not very friendly but fair, intimidating. And Lord of the Dead. I'm thinking pathologist.
Demeter: nurturing, values hard work, likes children. Teacher.
Hestia: the least-known Olympian, all we really know about her is that she is Goddess of the Hearth with home, she gave up her throne for Dionysus to prevent fighting, and she swore to never marry because Poseidon and Apollo both proposed to her and would've gone to war over her. In other words, huge pacifist with family ties. Maybe a community leader of volunteer.
Apollo: so many possibilities. Musician, composer, rock star, doctor, poet, hipster, psychic. Take your pick.
Artemis: perhaps an animal rights activist. Or environmental activist. Or feminist. Or girl scout troop leader. Or OB/GYN.
Athena: lawyer, professor, mathematician--a position of culture and intelligence. She's also the Goddess of Arts and Crafts, particularly weaving, so I could see her being an artist of sorts.
Hermes: he could probably do anything he put his mind to, honestly. If I had to choose, I would go with a social media guru, traveling salesman, public speaker, pickpocket, conman, professional athlete (namely running), businessman, or someone in finance.
Ares: someone in the military would be an obvious answer. Or possibly a mafia enforcer. Or a nomadic cage fighter, like Wolverine at the beginning of the first X-Men movie.
Aphrodite: model, actress, singer, talk show host, anchorwoman, any kind of celebrity that depends somewhat on her physical appearance/appeal.
Hephaestus: engineer, mechanic, software designer, rocket scientist. Whatever involves him creating something or other.
Dionysus: fancy vintner, or someone who makes illegal moonshine. Possibly a theater bloke who smokes weed backstage.
