This page contains information regarding Star Trek: Lower Decks, and thus may contain spoilers.
Tendi attended Starfleet Academy, and graduated, a member of the science division. Strangely however, she 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. (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. She 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. She hand-edited The Dog's genetic sequence 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. This was at least partially due to the fact that Tendi had never met an actual dog. (LD: "Much Ado About Boimler")
D'Vana Tendi was quite fond of 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 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, but despite this handicap, Tendi was only excited 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!"
- - T'Ana and Tendi, lying to the former over the time it would take to repair a biobed (LD: "Temporal Edict")
- LD: (every episode)
D'Vana Tendi was voiced by Noël Wells.
In developing the characters for Star Trek: 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.