This page contains information regarding Star Trek: Lower Decks, and thus may contain spoilers.
Her admission to the Academy was very difficult for her, as the preexisting stigmas surrounding Orions resulted in most seeing her as little more than a pirate or thief. This made her very sensitive, and prone to frustration when anyone would associate her with stereotypes surrounding the Orions, but also incredibly eager to prove herself as a valuable crewmember. (LD: "We'll Always Have Tom Paris")
She strangely never finished her course at the Academy which trained her to space walk, and was simply given a B grade regardless. Tendi never questioned this until much later, believing it to most likely have been a clerical error. (LD: "Terminal Provocations")
One of Tendi's early assignments was a stint at Outpost 79 prior to being transferred to the USS Cerritos in 2380, where she was assigned as a medic under Nurse Westlake. On her first day, she met Ensigns Bradward Boimler and Beckett Mariner, who gave her a tour of the ship and introduced her to Ensign Sam Rutherford. When the rage virus broke out on the Cerritos, Tendi assisted Dr. T'Ana in treating the infected, and was even ordered to manually pump Lieutenant Commander Stevens' heart with her own hands. (LD: "Second Contact")
Tendi showed a significant proficiency in genetics when she created The Dog, an artificially-created dog made from inert carbon, as a personal side project. She hand-edited The Dog's genetic sequences to make it 5% faster and 6% smarter than the average Earth canine. In addition, The Dog possessed augmented abilities lacked by the typical dog, including shape-shifting, hovering, and spitting lightning. These augmentations were at least partially due to the fact that Tendi had never encountered an actual dog. (LD: "Much Ado About Boimler")
Tendi was known to be incredibly enthusiastic, and optimistic in almost everything she did. She valued her friends on the Cerritos, and took interest in any task she was given. While others paid little heed for her positive nature, it very rarely ever bothered her, and only made her push herself even harder to do a good job at any given task. She was slow to anger, and incredibly patient, and very rarely let others affect this attitude. She also valued the happiness of her friends over that of her own, though this indirectly made her hesitant to talk about herself much.
She was good at her duties in sickbay, but Dr. T'Ana noted that more often than not, she was not very assertive, and often let her crewmates walk over her. However, T'Ana was also impressed by Tendi's prowess for the job, and when she showed more confidence, she commended her for it. (LD: "Mugato, Gumato")
While she was better known for her enthusiasm on the job, she was also quite sensitive when it came to stereotypes, or even the direct culture of her Orion heritage. Her discomfort was a key reason for her eventual entry into Starfleet, and she did her best to distance herself from her connection with the Orion culture. When it was brought up, she was noticeably uncomfortable with it, and hesitant to talk about it. (LD: "Crisis Point", "We'll Always Have Tom Paris")
D'Vana Tendi was quite fond of fellow ensign Sam Rutherford, with him being one of her first close friends on the Cerritos. When passing by the Trivoli pulsar, Rutherford attempted to switch jobs on the Cerritos so that he could watch the pulsar with her, and not be busy with maintenance in the ship's Jefferies tubes. However, when this didn't work out for him, Tendi offered instead to watch the pulsar with him on a PADD while he worked in the Jefferies tubes. (LD: "Envoys")
After Rutherford was seriously injured in a conflict with the Pakleds, which resulted in the loss of his cybernetic implant, Tendi stayed by his side, and often read engineering manuals to him while he was unconscious. His injury affected his memory, and he did not remember who Tendi was when he woke up. Despite this handicap, Tendi was simply excited, as she believed that they would both be able to become best friends again. (LD: "No Small Parts")
"Ensign D'Vana Tendi, reporting for duty. I'm a transfer from Outpost 79."
"Deck 4. Follow the yellow line. Take the turbolift all the way down."
"Thank you so much! And can I just say that I'm really honored to be—"
"Keep it moving, lower decks. Next!"
"Still uh, happy to be here?"
"Are you kidding? I got to hold a heart!"
"Tendi, how long will it take to repair a biobed?"
"Oh, that would take about five... hours."
"Excuse me? That's great!"
- LD: Every episode
Tendi is voiced by Noël Wells.
In developing the characters for Lower Decks, Mike McMahan described all four leads in an 10 August 2020 TrekMovie.com interview as a combination of other Star Trek characters, parts of himself, and people in his life. Tendi developed from a suggestion by Secret Hideout that the first episode feature a character's first day on the ship. From there, McMahan took to Tendi as a character that was "all silver lining," relating how he would act on a starship. Tendi was further described as "that voice of enthusiasm... who just wants to know everything and wants to consume all things about the ship and learn and grow... who we will also watch grow throughout the series." 
Tendi appears as a duty officer in Star Trek Online.