Felicity worked at Queen Consolidated for Walter Steele. Walter and Oliver separately asked her for help leading her to believe Oliver was The Hood, and he brought her on board his team. Felicity now works alongside Oliver and Diggle as a trusted member of The Arrow team.
Ray: Advanced Technology Operating Mechanism. ATOM.
Felicity: What are you going to use it for?
Ray: To protect the people of this city. And I want you to help.
Felicity: Why does this keep happening to me?
Ray: How many abandoned warehouses are in this city? No, no, I'm genuinely curious.
Oliver: Stay focused, Ray.
Felicity: Maybe Simmons isn't in there.
Oliver: Do you get this anxious when I'm out in the field?
Felicity: I genuinely cannot think of an answer to that question that does not get me in trouble.
[Diggle looks at Oliver, shakes his head no]
Ray: There's not a visual sighting or any reading at all from the ATOM. I mean the suit, not myself in the third person.
Oliver: There's a decent chance that you and Palmer are related.
[Sarcastic glance from Felicity and return side glance from Oliver]