Inside the Los Angeles headquarters of Stiiizy, America’s largest cannabis brand by sales, a robotic machine takes ten pre-rolled joints in its arm, dips them into a vessel of THC concentrate and then into another bucket filled with kief, a potent dust-like form of cannabis. In a few seconds, the Stardust machine, made by Van Nuys-based Sorting Robotics, will have coated 30 pre-rolls with an extra punch of THC, the compound in marijuana known for getting people high. In an hour, Stardust, and its one human operator, will have produced about 1,000 joints ready for consumption.
“This machine’s output could be more than ten people,” says James Kim, the CEO and cofounder of Stiiizy, while standing next to the Stardust in early April. In another room down the hall, about 140 employees sit at 14 tables, manually dipping joints into a terpene-infused adhesive and rolling them into a pile of kief. Stiiizy isn’t ready to replace its humans just yet, but Kim does envision a day when all of its joints will be made entirely by machines. “Robotics is the future, but the future isn’t today,” says Kim. “It might take a lot more time.”
That future is being pioneered by Sorting Robotics, founded by Nohtal Partansky (its CEO), Cassio Santos (CTO) and Sean Lawlor (who was the COO before leaving last year), in 2019. The company has sold about 30 Stardust machines, which go for a hefty $250,000 each, as well as hundreds of lower priced marijuana machines to cannabis brands since its founding. Sorting Robotics also makes the Jiko, which injects joints with THC concentrate, making what’s called a “donut” in pothead lingo (when the joint is lit, the ember resembles an “O” as the concentrate vaporizes in the middle as the plant material burns.), and the Omnifiller, a vape cartridge-filling machine.
The company, which has 20 employees, is still tiny—it will reach $11 million in revenue this year, up from $7 million last year—but Partansky, like many cannabis entrepreneurs, is playing the long game, hoping the drug will eventually be legal at the federal level.
The company does have something going for it: profitability. Sorting Robotics has been in the black since 2021. While Stiiizy ($800 million in 2024 sales) is America’s largest weed brand, Sorting Robotics’ client list also boasts bigger companies by global footprint, including Canada-based Tilray ($788 million in 2024 revenue), and smaller regional outfits in the U.S. such as Blue Fox Brands (sales: $80 million), which sells its pre-roll brand Cali Blaze across Colorado, Massachusetts and Michigan.
“Stardust allows you to replace the labor that you already have with something that's five to 10 times more efficient,” says the 35-year-old Partansky. “It [can] improve your margins by 10-plus percent.”
In the complex world of the state-regulated cannabis, which generated $32 billion in sales last year in the 40 U.S. states that allow medical, recreational or both, better margins can be life-or-death. Only 27% of marijuana businesses are profitable. Most companies fail. Pre-rolled joints are the third biggest product segment in terms of market share (after flower and vape pens) accounting for 16% of all cannabis sales, according to a report by Headset, a Seattle-based cannabis data firm. It is also the fastest-growing category in the industry: In total, 394 million individual joints were sold last year, for $4.1 billion, a 12% jump over 2023. More than 43% of all pre-rolled joints are infused with extra THC, which explains Sorting Robotics focus on the subcategory.
But questions remain about how much the market can expand in the short term. Currently, there are only a handful of cannabis companies that produce enough THC-infused pre-rolled joints to make a $250,000 investment like the Stardust make sense financially. Since marijuana is still illegal at the federal level, state-regulated cannabis companies cannot ship product over state lines, meaning products sold in a state must be made in that state, hamstringing manufacturers from creating one giant facility and shipping across the country.
And there is good reason companies still employ janitors to sweep floors despite the invention of the Roomba and commercial versions of robotic sweepers like Avidbots’ Neo. Robots are expensive and finicky while laborers are cheap and require minimal training. That $250,000 price tag does not include maintenance or operating costs.
At Blue Fox Brands’s manufacturing facility in Lansing, Michigan, Sorting Robotics and human employees work side by side every day. Two employees infuse about 6,000 joints during an eight-hour shift by hand, costing the company about four cents per joint. The Stardust machine, assuming it is working flawlessly, is marginally cheaper, infusing just as many joints during that shift, each three-and-a-half cents. “It’s worth it if you’re about volume,” says Blue Fox Brands founder and CEO Kosta Marselis. “It does its job basically every single time and makes pretty joints.” But when you factor in the hour it takes to clean the Stardust between batches of different types of joints and the fact that the Stardust wastes more THC oil and kief than human infusers do, Marselis says the output between human and machine is “basically the same.”
In a state like Michigan, the $250,000 investment for the Stardust is worth it because the price of oil is low, about $1,000 per liter, and the market can handle the machine’s high volume. But Marselis says he probably won’t buy a Stardust for his operations in Massachusetts, where the price of THC oil is $4,000 and the market cannot handle as much volume.
Partansky is not a traditional weed entrepreneur—he is a robotics nerd. These days, he usually takes edibles to help him sleep but will occasionally hit a joint, especially one that was made by one of his machines. Born in Manhattan and raised in Los Angeles, he became a professional Magic The Gathering player in high school. “I was really into Magic, at, like, an uncomfortable level,” he says. He attended University of California-Davis for mechanical engineering in 2013 and graduated from Georgia Tech with a master’s degree in aerospace engineering in 2015.
His first job was an internship at XCor Aerospace, a private space flight startup in the Mojave Desert. While there, he realized that rocket science was “less magic and more kitchen sink,” he says, and that the founders of the company were very smart, but not unattainable geniuses. After launching his first company—Lathon, a 3D printing firm—while getting his masters, he landed a job at NASA’s Jet Propulsion Laboratory, working on the MOXIE project, a device that produces oxygen on Mars. But he soon got the itch to start a new company, one closer to his heart. In 2018, he launched Sorting Robotics to first make a machine that organized Magic The Gathering playing cards, a process that can take days to do manually.
“Sorting cards was the bane of everyone’s existence,” he says.
But Partanksy and his cofounders wanted to build a company with a larger potential market than a “children’s trading card game,” he says. At the end of 2018, the trio applied to the startup accelerator Y Combinator and got accepted. They spent five months cold-calling companies in different sectors, looking for one that was ripe for automation. That’s when they came across the cannabis industry.
“We had friends who had just started legal cannabis companies, and they basically said, ‘Hey, there is zero automation in this space, just build anything,’” Partansky remembers. “We didn't really know what we were doing, but we identified the problem set. At the end of 2019, we raised a few million dollars out of demo day to go after the cannabis market.”
With $3.5 million in funding from Splash Capital, Night Owl Ventures and Genesis Ventures, the founders sold their Magic The Gathering card sorting company for a nominal amount and launched a cannabis manufacturing and packaging business, in Oakland to learn about the industry. They soon realized infused pre-rolls were popular but time-consuming to make by hand. (Partansky sold the co-packing business to a dispensary chain in 2022 after the California weed market started tanking.)
After a couple years of development, the trio launched their first cannabis robot in 2021: the Jiko, which infuses joints with THC through an injection process—a needle filled with cannabis concentrate fills the inside of the joint with mind-bending rosin or distillate. It sells for $90,000 and can infuse 1,000 joints an hour. The next year, Sorting Robotics launched the Omnifiller, a $150,000 machine that can fill 6,000 vape carts with THC concentrate an hour. Last year, Sorting put the Stardust on the market, its most advanced and most expensive robot yet.
For Partansky, the path from NASA to weed robots was less of an aha moment and more of a slow, iterative process, something he learned while working on the Mars rover. Today, he believes Sorting Robotics has a culture that is a mashup of a federally funded high-tech firm and a fast-moving tech darling.
“Sorting Robotics is like if NASA and Facebook had a baby,” Partansky says, without a tinge of irony considering his company is microscopic compared to either of those two behemoths. “We ship things fast and don’t break anything. Robots are expensive—don’t break the robot.”
There are a handful of competitors in the cannabis robotics industry, from Action Pack to Accelerant to Roll Pros. But the real giants—the companies that make cigarette manufacturing equipment —have largely remained on the sidelines. Germany-based Körber (2024 sales: $3.2 billion) has been producing cigarette rolling machines, which can make 20,000 cigarettes per minute, for 79 years. The company recently expanded into the hemp market with its Nano-H machine, which can roll 5,000 joints per minute at a cost of two cents each. Partanksy says joints, and especially infused joints, are too specialized (“It grinds differently. It burns differently. It's fabricated differently,” he says.) for these machines to take over the marijuana industry just yet, but its more likely the big boys are wary of entering a market that remains illegal at the federal level.
But Big Tobacco—and its highly efficient rolling machines—will come for cannabis when legalization finally arrives. The federal government may soon restart the stalled marijuana rescheduling process that was started under President Joe Biden. In early August, during a press conference at the White House, President Donald Trump said: “we'll make a determination over the next few weeks." The process could end with marijuana being reclassified from a Schedule I drug (alongside heroin and LSD) to a Schedule III drug (think Tylenol with codeine). That would help the industry because it would give pot companies full access to the American financial system. If weed is rescheduled to a more lenient category, Partansky envisions a future in which cigarette machine manufacturers would look for an easy way to get into the burgeoning cannabis industry – and his company is very much for sale.
“It could go federal between now and the next five years at any point in time,” says Partansky. “And I think when it does that, the tobacco companies or manufacturers that service those industries don't have any market share in this industry. So, they're just going to come in and buy me.”