During the Galactic Civil War, an undercover agent worked for the Alliance to Restore the Republic. Some time after the Battle of Yavin, that agent was as tasked with locating a hidden droid factory on the planet Tatooine, where the Galactic Empire had developed a new series of assassin droids ready to wreck havoc on the galaxy. To give themselves the means of performing that mission, the agent infiltrated the Nkik clan of Jawa, learning the art of droid building under the aegis of Wimateeka. The Rebel agent had to equip several droids with the capabilities they needed to meet the challenges of various missions, such as the ability to talk, arms that could manipulate pulleys or enough power to push crates up inclines. After those training missions were completed, the agent recovered a set of Optical Information Crystals that revealed the location of the hidden factory. Thanks to a program code reconstructed by putting the crystals' informations together, the Rebel droid builder managed to re-program the Imperial assassins droids into harmless, dancing ones.
At the time of the Galactic Civil War, a diminutive humanoid served within the Alliance to Restore the Republic, also know as the Rebel Alliance, a resistance movement that opposed the tyranny of the reigning Galactic Empire. Despite being still young, that individual became one of the Alliance's most trusted secret agents. One day, the Alliance Intelligence reported that the Empire had built a secret droid factory somewhere on Tatooine, a desert, suns-scorched planet in the Arkanis sector. They also learnt that Imperial engineers were creating a new series of assassin droids in that place. Once completed, those dangerous machines would be released to wreak havoc in the galaxy. Intent on locating that hidden factory and reprogramming the droids, the Alliance executive entrusted the diminutive agent with that mission.
The agent was brought to Tatooine aboard a CR90 corvette, where they received instructions from C-3PO and R2-D2, a droid duo affiliated with the Alliance heroes Luke Skywalker and Leia Organa. The agent was ordered to pose as a Jawa so he could gain entrance to the sandcrawler of the Nkik clan with the connivance of its leader Wimateeka. After learning to build droids with the Jawas, the Rebel was tasked with creating a robot that could infiltrate the Imperial factory and reprogram the new assassin droids. To assist them in that mission, the agent teamed up with C-3PO, R2-D2 and Cammy, a chatty Holocam E-series droid.
With the help of his mechanic partners, the agent learnt the art of droid building in the of Wimateeka, proving worthy of the latter's approval. He or she put newly built droids through a series of tests and maneuvers in the wastes of Tatooine, preparing for the actual infiltration mission. As a first step, the Rebel tested their droids in the Sandcrawler Training Facility. In that area, the agent could study their new droids' movement, test their speed or their ability to jump, and check if they were magnetic or not.
Following the preliminary test, the Rebel operative began Wimateeka's first training mission. The wheeled droid had to pass through a security exit door located at the top of the cliff in the Jundland Wastes. To that end, the droid had to put in place a series of movable enclines by activating switches, taking account of its speed and weight to determine the appropriate slope angle. When the inclines were set, there remained a sizeable gap between the top of the slope and the exit door, which the droid was forced to fill by pushing a wooden crate up the incline. The same mission was repeated once more, although with a legged droid, forcing the droid builder to revise their strategy.
In the second test, the agent had to get a droid across two moving conveyor belts that were used to carry crates containing magnetic items. In order to do so, the builder created a droid that was magnetic itself so it could be pulled off the ground by the trams picking up the crates. Againt, that mission was repeated twice with new objectives. On the second round, the builder's droid was tasked with rescuing a stranded R5-series astromech droid that had run out of battery power. In order to help the astromech unit, the agent's droid had to pick up a battery located on the other side of the conveyor belts. On the third occurrence of the mission, the agent had to save another stranded droid that needed to be fully re-powered through a power plug and a generator.
The Rebel agent was awarded a Jawa droid builder certificate.
After a series of supplementary missions during which the Rebel agent learned how to build droid, it became necessary to recover a program code that could render the assassin droids harmless. In order to do so, the agent had to recover several Imperial Optical Information Crystals and take them to the Jawa Data Crystal Information Area, where they could be activated with a laser light generator. One of those crystals was kept in the Mos Eisley Salvage Yard, another in the Phrik Mines, and the last one was kept by a moisture farmer who supported the Rebel Alliance. While the droid builder had just reconstituted the program code, the Jawas informed them that the Imperial factory had been located in the second quadrant of Tatooine.
Eventually, the The Rebel ended up building their best droid and had it take a disk with with the program code to the hidden factory, the location of which was now known. The robot trespassed into the Imperial factory and reprogrammed the assassin droids into dancing ones. Wimateeka was so proud of his recruit's work that he awarded them with an official droid builder certificate.
The droid builder was the player character of the Star Wars: DroidWorks children-aimed game. The game never specifies the Rebel builder's name or gender, allowing the player to identify themselves with the character. Unlike other game characters—like Rookie One from Star Wars: Rebel Assault or Meetra Surik from Star Wars: Knights of the Old Republic II—the Rebel builder has not been reused in later works, and thus was never given a proper canonical identity.
C-3PO comments how the young Rebel looks good as a Jawa, which hints this secret operative might have been a child at the time. This seems to be backed up by the droid builder's diminutive height.