Lisa Oh was a human Starfleet engineer serving aboard the USS Cantabrian from 2372 until 2373 and then aboard the USS Cantabrian-A from 2374 until 2376.
Lisa Oh was born in 2350. She entered Starfleet Academy in 2368 and graduated sometime in 2372.
On her first mission, she bumped into Captain Noah Wrightson (who was touring engineering) and, when asked, she said she felt her posting to the Cantabrian was a “dream come true”.
During that same mission, Oh was one of the engineers helping Lieutenant Commanders Elizabeth Singh and Ethan Arden comb through data on flight recorders to find out any information they could on the Myhr’an. (“Catalyst, Part One“)
Oh held the rank of ensign and worked with Cantabrian-A chief engineer Milami Thall. Early in the year, she was one of four officers in the USS Determination‘s main engineering when the Vendoth attack caused HEIDI to malfunction, killing her. (“Howl“)
In 2372, the other engineering cadet assigned to the Cantabrian was Oh’s classmate and close friend, Samuel Morgan. Every day they would walk together to and from their shift. One day, when Oh’s boyfriend Nelson wouldn’t answer the door-chime, Morgan kept a look-out for Oh as she tried to break in. Another day, suspecting something was wrong with the odd-behaving Nelson, Morgan helped Oh comb Nelson’s quarters for anything out of the ordinary. They found his body, and Morgan consoled Oh on her loss. (“Catalyst, Part One“)
Obviously, Elizabeth Singh and Lisa Oh became close friends in a short period of time as, before dismissing them after a long day, Singh said something to the group but pointed at Oh, who blushed. The development of this friendship wasn’t shown during the story, but it is assumed that during working together, Oh may have shared some personal details with Singh. (“Catalyst, Part One“)
In 2372, Lisa Oh was romantically involved with Nelson. He stood her up (which, she admitted, wasn’t like him) on a date, but Oh later found this was due to the real Nelson being dead. She discovered his body with Samuel Morgan, and she was very upset at the loss. It is not known where they met or when they started dating but it is assumed this was at Utopia Planitia Fleet Yards or earlier as Oh had Nelson’s pass-code to his quarters, indicating a serious relationship. (“Catalyst, Part One“)