From 2017 to 2018, she served as the managing attorney at the Immigrants' Rights Project at Community Legal Services in East Palo Alto, California.

[4][failed verification] She has also worked at the ACLU and at the Legal Aid Society-Employment Law Center.

[2][3] Martínez-Olguín was a member of the American Constitution Society Bay Area Lawyer Chapter's board of directors from 2015 to 2022.

President Biden nominated Martínez-Olguín to the seat vacated by Judge Jeffrey White, who assumed senior status on February 1, 2021.

[8] On January 3, 2023, her nomination was returned to the President under Rule XXXI, Paragraph 6 of the United States Senate; she was renominated later the same day.