On a chilly Wednesday evening in October, the sounds filling Ambre Romero’s home were familiar: her grandchildren unloading the dishwasher, her husband, just off work, watching television. Ms. Romero was getting ready for her shift serving cocktails at the MGM Grand Detroit, the casino where she has worked since 1999. She pulled on her blue bustier top, said goodbye to her family and drove to a nearby gas station to pick up Red Bull and Lucky 13 scratch-off tickets.

Ms. Romero, who has long reddish-brown hair and a wry smile, enjoys the predictability of her nights. Her shifts revolve around the regulars, whose families, health problems and pet names she knows well. The work is unceasingly social, which is just how Ms. Romero likes it; she’s a former dancer who turned to cocktail serving because it felt like performing.

But Ms. Romero, like so many millions of Americans, has seen her job remade in recent years by the arrival of new technologies automating parts of her work.

When ChatGPT was released, about a year ago, public focus shifted to the knowledge economy jobs that artificial intelligence could transform, from law to copy writing. Goldman Sachs predicted that the equivalent of some 300 million full-time jobs could be automated with generative A.I., the technology that can create texts, images and sounds in response to prompts.

But long before generative A.I. products reached the market, tens of thousands of jobs in hospitality — a field not known for being a face of automation — were already shifting under the pressures of robotic technologies: robots that deliver room service, prepare salads and check in hotel guests. In the accommodations and food service industry, 70 percent of workers could see more than half their work activities automated, including by artificial intelligence, according to a McKinsey estimate this year.

“The new thing is the risk to white collar workers, but blue collar workers have faced this issue for a long time,” said Darrell West, senior fellow at the Center for Technology Innovation at Brookings Institution.

Changes in the comfortably predictable rhythms of Ms. Romero’s job began with the arrival of Smart Bar systems, or automated cocktail dispensers, in 2019, which came with what she described as a quick, surface-level training. She found herself dealing with machines that malfunctioned by spraying liquid on the servers and often lacked the items that customers had ordered. Ms. Romero spent more time tending to the machines and less time chatting with customers, a change that she found reduced her tips by about 30 percent.

“I don’t know anyone who cares for the Smart Bar,” said Ms. Romero, who makes just over $13 an hour. “It increases all of our responsibilities. We went from being just a server to a bartender and a bar server.”

Upstairs, along the MGM Grand’s hallways where housekeepers wheel their carts full of cleaning supplies, new technologies have also been remaking work. Since earlier this year, more housekeeping tasks have been facilitated through an app, called HotSOS, which assigns workers to rooms for cleaning and instructs them on the sequence in which to clean them. But the app sometimes malfunctions, assigning a worker to a room that still has a guest in it or losing service entirely and leaving workers confused.

For housekeepers, this has been a vexing factor in their carefully choreographed routines.

“You start to get crazy — especially when you know you have certain rooms you have to get to,” said Alicia Weaver, 60, a housekeeper who has been working at the MGM Grand since 1999, and makes $17.76 an hour. “It gets frustrating when you have to stand in the hallway trying to figure out how to get into a room.”

When new technologies arrived, Ms. Weaver was told they were supposed to make her job easier. Instead there are moments when HotSOS freezes, has to be rebooted and then erases its records of the rooms she has cleaned.

MGM Grand executives declined to comment about their use of robotic technologies. Some casino workers said that they had welcomed new forms of automation in their work because it eases their workloads. They don’t oppose the technology; they just want to be warned of its arrival, and see their criticisms taken into account.

“I actually was a little bit excited about it,” Denita Anderson, a housekeeper at the MGM Grand since last year, said about HotSOS. “I thought it was convenient.”

A co-owner of Smart Bar’s manufacturer argued that the technology helped workers prepare drinks faster, meaning they could serve more customers and get more tips. “Bartenders make more money by serving more drinks,” said Barry Fieldman, a managing member of Smart Bar USA. “Guess who wins when that happens? The bartender makes more money and so does the house.”

“You’re not going to negotiate technology away,” Mr. Fieldman added. “You’ve got to find a way to train employees, show them how the technology is going to help them make more money so they become less fearful of it.”

And Amadeus, the company that makes HotSOS, said its technology had helped workers transition away from stodgy systems in which room assignments were made on paper, and allowed housekeepers to do their work more quickly and safely.

“This work flow reduces the need of having to move housekeeping carts around the property unnecessarily, ensures scheduled breaks and provides the most efficient way to accomplish their daily tasks,” said Alberto Santana, the company’s senior vice president of sales, adding that the company’s customer service team responds to all the feedback and complaints it receives.

On Oct. 17, Ms. Romero, Ms. Weaver and some 3,700 of their colleagues went on strike, after their contract expired and as the unions representing them — including UNITE HERE Local 24, United Automobile Workers Local 7777, Teamsters Local 1038, Operating Engineers Local 324 and the Michigan Regional Council of Carpenters — continue to negotiate for a new contract. Many issues at the heart of the talks are standard, including higher wages that keep pace with rising costs of living, more stable schedules and more funds for health care.

But the technologies that hotels and casinos use are also part of the negotiation. Workers want to be a part of conversations about their implementation and use.

The union is demanding at least six months’ notice when new workplace technologies are planned, the opportunity to negotiate over how the technologies are used, training on how to use them and severance packages when unionized workers are laid off because of new technologies. (About half of UNITE HERE’s members across the country have already secured similar provisions.)

These provisions would apply to Smart Bar and HotSOS, but also many other technological products, including those that workers say raise threats to safety. For instance, ordering technology, like tablets, sometimes allows minors to order drinks and leaves it to the servers to decide whether to hand the cocktails over, which could agitate the customers.

“You’re used to doing your job in a certain way for many years, and then they come one day and say, ‘Well, we’re going to change that,’” Ms. Weaver said. “If you’re going to roll something out, everybody should have a good understanding of how it works.”

Detroit has long been a union town. Ms. Romero’s father was a foreman at Chrysler and a shop steward for the union. Ms. Weaver’s parents were also involved with their factory unions; her most vivid childhood memories are of the carnivals organized by the U.A.W., where she rode roller coasters and snacked on cotton candy and buttermilk potato chips.

The historians Marvin Surkin and Dan Georgakas, in their book “Detroit: I Do Mind Dying,” chronicle the arrival of new forms of automation at Detroit’s car factories in the 1970s — which made the work faster, but also degraded working conditions.

“With fewer workers and fewer work hours, they were trying to get more production down the assembly line,” Mr. Surkin said. “That has an effect on morale, on work-life balance.”

And as for the casino workers today, “it’s the same old story,” Mr. Surkin said, adding that he’s not surprised the city’s hospitality union workers are fighting the negative effects of automation: “In Detroit, they have generational memory.”

In hospitality, the effects of new technologies have been subtler. Often they’re being used for partial automation, meaning jobs are changed but not eliminated.

In early October, Ms. Romero stopped at the Teamsters hall, right near the MGM Grand, to greet union staff members and volunteers who were assembled to prepare for a potential strike. She walked into the hall trailed by her grandson, who was kicking a ball.

“Y’all coming to pick up your strike money?” a union staff member asked. Another pointed to Ms. Romero’s grandson, asking, “So this is the boss?”

Inside the fluorescently lit space, volunteers stapled cardboard sticks to posters with large images of dice, which read, “Don’t gamble with our future.”

The workers like to remind their employers, and one another, all that they’ve invested in their jobs. Ms. Weaver got carpal tunnel syndrome from tucking sheets under beds, back pains from lifting mattresses and swollen legs from being on her feet all day.

Ms. Romero, meanwhile, gets irritated when she gets an order for a drink that the Smart Bar doesn’t have, and then runs across the casino trying to find a bartender who will serve it. By the time she gets back to the customers, they may have left, meaning her time was wasted.

“Because of the difficulties that we run into with the Smart Bars, I’m constantly rushing,” she said. “I still enjoy my job — it’s just a lot harder now.”