Inside the cavernous warehouse, countless items were being shuttled through a nest of aluminum chutes and slides and carousels, and temporarily housed in hundreds of shelving units and bins. It was unnervingly quiet: The only background noises were a dim machine hum whose source was imperceptible, and the occasional blip or bleep from forklifts and carrier vehicles moving about the space. The floor manager barely had to raise his voice to be heard.

“It’s important to remember,” the manager said as he guided us around the space. “This is not a warehouse. It is a distribution center. Nothing stays here longer than 48 hours.”

The first worker we met was a middle-aged woman, let's call her Susan, who was assigned to the “picker” station where shipping containers with the appropriate product items for each customer order are filled. She stood in front of a tall shelving unit and wore padded braces around both her arms and knees. Dozens of bins on each shelf took turns lighting up red and Susan’s hands promptly followed, retrieving items and dropping them into a larger container on the conveyor belt behind her.

One LED screen instructed Susan on how many items to retrieve from each bin. A second LED screen displayed a timer which kept track of her fill rate, basically the only productivity factor on which pickers are evaluated. Susan was on pace to “pick” about 120 items an hour (just below the cited industry standards ranging from to “200 to 400 items an hour”). The job operates on a kind of arcade game logic: a plethora of blinking lights and rapid directional movements, all playing toward the ultimate goal of marginally more dexterous speed and a new high score.

Susan and her co-workers appeared in good spirits as the manager introduced them by name and told us how long they had been working at the company. About half of the workers had a mental or physical disability, a result of the company’s “inclusion” program which mirrored similar efforts at other major retailers. In a news segment about a DC in South Carolina, one disabled worker said hers was “the coolest job in the world.”

These programs are viewed as leading examples of combined corporate and social success, but that success may be short-sighted. Pickers and low-skill jobs of the sort represent a pain point for DCs and the e-commerce executives who are managing their evolution. The jobs appear simple (one Amazon executive referred to the workers as like “robots in human form”), but the tasks are difficult to automate at scale: “Because products vary so much in size and shape and because of the way they sit on shelves, robotic manipulators still can’t beat real arms and hands,” explains Erico Guizo on Spectrum, the blog for the Institute of Electrical and Electronic Engineers (IEEE).

Unlike Susan and her co-workers, who were salaried and long-time employees of the company, a growing number of “pickers” at DCs across the country are hired through staffing agencies and classified as “non-permanent” or “temporary.” This means no health care coverage or benefits, pay that's usually barely above the minimum wage, and employment that can be voided at a whim when the workers are no longer needed.