This story's great. I've only read over the first part, but it's believably dystopian, claustrophobic, but most of all I love how concisely phrased it is, particularly in the early action sequence at the subway station.
While simple in structure compared to other stories, which typically employ extended descriptions of the environment to convey the dystopian theme, it instead focuses on the thoughts of a single character, interspersed with light causal observation made by that character.
It really captures the rushed, haphazard, practical style of thinking a person in such an environment would rely on in order to survive.
Conversely, I also appreciated the detailed retrospective prelude as well. It reeks of effort that is of a higher tier compared to similar companion passages to fembot/dystopia themed writings on the wiki that I've read, and Portia is complex, logical and believably self aware given the setting.
Great job!

"Machines smart enough to do anything for us will probably also be able to do anything with us: go to dinner, own property, compete for sexual partners..."