[1] During her fellowship as an EIS officer, she investigated the 1996 international outbreak of E. coli O157:H7 that was linked to unpasteurized Odwalla apple juice, which killed a 16-month-old girl and sickened 70 people, of whom 25 were hospitalized and 14 developed the hemolytic uremic syndrome.

[4] She also led an investigation into a salmonella outbreak in Santa Clara County that was traced to cheese made from raw milk and sold in local Hispanic markets.

[1][8] Along with other public health officers in the region, Cody was largely credited for promptly advocating for measures that would limit the spread of COVID-19 when the pandemic reached the United States in 2020.

[19] Following one news conference, she became the subject of a viral meme, after she implored citizens to refrain from touching their faces, then licked her finger to turn a page.

In late August, the Santa Clara County Sheriff's Office announced that they had arrested a man suspected of sending her several threatening letters that used language typical of far-right movements.

[20][21] On several occasions Cody has cited the effectiveness of the enacted mandates without providing data or evidence to back up her claims.

[23] At a meeting of the Santa Clara County Board of Supervisors in September 2021, Cody cited masks as the reason why Santa Clara County had minimal influenza cases in the winter of 2021, and was reminded by a supervisor that the entire area was under shelter in place at that time, with only essential businesses open.