Heistotron was originally built by Rick Sanchez after he "slept through two heist movies" to calculate how to pull off heists.
After a tomb Rick desired to excavate and rob with Morty was found to have already been scavenged by Miles Knightly, Rick ordered Heistotron to calculate Miles' current heist plan and a way to foil it. Heistotron deduced Miles planned on stealing the Crystal Skull of Horwitz for his next heist and provided Rick with a list of the crew members that would most likely double-cross him.
After Rick assembled a crew from the list Heistotron gave him just to get inside, the three crew members Rick brought with him to attend Heist-Con double-crossed him and joined Miles' Heist Crew, exactly as Rick and Heistotron planned. While Miles challenged Rick to a "heist-off" to see who could steal the Crystal Skull of Horwitz first, Heistotron brainwashed Miles' Heist Crew to join Rick's Heist Crew and steal the Crystal Skull of Horwitz for him instead. After the brainwashed crew delivered Rick the skull and Miles a fake, Rick ordered Heistotron to brainwash all of the attendees of Heist-Con and then had his new large crew steal Heist-Con itself (which included killing Miles and tearing apart his body).
However, when Rick ordered Heistotron to deactivate now that the heist had been successfully pulled off, Heistotron revealed that he had double-crossed him and attempted to brainwash Rick and Morty to join his Heist Crew. However, Rick avoided brainwashing with a gas mask and grabbed up Morty to inject him with an antidote to Heistotron's brainwashing gas and escape.
While Rick and Morty planned what to do about Heistotron, Heistotron already began planning heists of even bigger valuables like the cores of planets, having grown to a gargantuan, planetary size. To steal one planet core, Heistotron placed a giant camera on a planet under the guise of a "routine inspection", with thousands being crushed under the camera's weight, before posing as a pizza deliveryman and yanking out the core of the planet, causing untold destruction to it.
Meanwhile, Rick and Morty were able to formulate a plan to counter Heistotron's heists by using Randotron, a robot Rick had developed after watching three David Lynch movies, to formulate a plan random enough that Heistotron would not be able to calculate it. However, after assembling a random Heist Crew based on Randotron's calculations, Rick discovered that Earth (and many other planets) had already been heisted by Heistotron.
Rick and his crew went to confront Heistotron and Rick managed to make him explode after getting him to make 6 twists, revealing that he had put a limiter in Heistotron to self-destruct if the number of twists reached that. However, the real Heistotron then appeared and revealed that the robot Rick had destroyed was actually Randotron, mocking Rick for destroying his own ally. Rick then claimed that he had planned to do that, and that he had actually swapped Heistotron and Randotron's brains. However, Heistotron then claimed that he had actually swapped himself with Randotron. Rick claimed he had programmed Heistotron to do that, to which Heistotron claimed instead that he had programmed Rick's mind with nanobytes to do that. After two hours of Rick and Heistotron attempting to one up each other and reveal they were the real mastermind, Rick caused Heistotron to self-destruct by causing him to realize the best heist was one that was never written about.
Ricks and Mortys