Zhi was born to Yang Wei and Yang Kei of Beijing and Shanghai China respectively. His father is a proud working crewman for the Starfleet Copernicus Shipyards where he oversaw construction plans for new starships and eventually ascended to the position of senior dockyard supervisor. His career influence had a profound impact on Zhi and Yu Yang's, brothers and sisters borne as twins. Together they had visited where his father would spend his day and watch as ships of the line were put into service.
As common with plenty of siblings, the Yang siblings were no different, as they bickered and teased each other throughout their childhood. Both Zhi and Yu made great strides to win the approval of one parent to another, where it got to the point of being legendary. The Zhi/Yu rivalry knew no ends, to the point where Zhi joined an amateur football team outside Shanghai refusing to play on the same team as her sister. Though the exchange would get heated, there was never a bitter dislike between the two, as both twins had a genuine love for each other. However that didn't stop them from teasing and humiliating each other when ever given the chance; almost to the point where an observer would see as childish and annoying.
That rivalry continued when the Yang's engrossed by their love of starships, thanks to their father's upbringing, would join Starfleet to train as engineering officers. During their academy years Zhi and Yu excelled academically often grading past the 90% percentile. Eventually Yu pulled ahead in the grades and was ranked 13th overall in her class year; Zhi was ranked 18th overall. At the request of both siblings and due to Starfleet practices at the time, the Yu twins were assigned to different vessels. Yu higher ranking had her assigned to the USS Galaxy, as they began their prolific five year mission into the outskirts of the Beta Quadrant in 2367 to 2372.
Yang's first assignment was on the USS Crazy Horse, an excelsior class cruiser attached with Starfleet's Task Force along the Romulan Neutral Zone. At the height of his tenure the Crazy Horse was attached with Starfleet Task Force against the possible Borg threat of 2369. Yang during those years was heading a damage control party for a ship that didn't go through much damage. As a result of his three years at the Crazy Horse, Yang took up an opening as a diagnostics officer on the USS Hood. So while he wasn't advancing as quickly as her sister Yu on the Venture, Zhi would finally get his career groove on the Hood as he was able to gain more field experience.
At the height of the tensions between the Dominion and the Federation before the outbreak of war, Yu and Zhi were united as the Hood and Galaxy were assembled to form the 9th Fleet. At this point in time, at the year 2373, both Yang's had risen to positions of Assistant Chief Engineers for their respective ships. So when war broken out between the two powers, fates would be so strange when the Chief Engineers of both the Hood and Galaxy were killed for the Yang's to only step up and take control. Both Yang's would earn commendations and promoted to take up as Chief Engineers for their respective ships. To say the coincidental connection between the two would be nothing less than bizarre would be an understatement.
When the war ended in 2375, Zhi Yang would be reassigned from the USS Hood, which by the end of the war, was a battle hardened mess needing massive refits. Due to Zhi's growing field reputation he was given a choice to apply for any ship he saw fit. Having bled and sweated through an entire war, it was surprising to no one that he wanted to be rotated to a ship with an exploration mandate. So in 2377 he was given that chance when the USS Europa of the new Luna Class vessels was launched to explore the Gamma Quadrant.
When he returned from the Bajoran Wormhole in 2382 he returned a changed man. Somehow the years of exploring and discovering new species and civilization had made him a more seasoned officer. One that had developed well rounded leadership and social skills. He also had a massive leap in confidence, after holding together a starship without re-supply from Starfleet bases for five full years. His sister ever the kidder would rejoice at the fact that Zhi had finally caught up with the 'big boys'. Zhi was just as glad, but was ready for a break. He would take a leave of absence for two years, taking back the sights of Earth and returning to his routes. After being refreshed in both body and mind, Yang would once again take uniform and be assigned to the USS Isoroku, a medium size cruiser of the line. His sister in contrast would outclass him with her assigned to the newly launched Sovereign Class, USS Yamato.