SAN FRANCISCO — Ivan Salgado, a 32-year-old bartender and server at his family’s Mexican restaurant in Chicago, volunteered to stop working in late March so his aunt wouldn’t have to lay off any other servers.

There weren’t many opportunities for hospitality workers such as Salgado under the city’s shelter-in-place order. But Salgado had his own car and figured he would have an easier time finding a side hustle than his co-workers. To make rent, he threw himself into working full-time for grocery delivery company Instacart, which has exploded in popularity during the coronavirus pandemic and is hiring 550,000 workers to keep up with demand.

“Honestly, I feel like I have no other choice,” he said. “There’s really no other place to work unless it’s working at a grocery store, doing delivery service like this.”

More than 38 million people have filed for unemployment nationwide in the last two months. At the same time, hundreds of thousands of gig jobs became available from businesses including Amazon, DoorDash, Instacart and Shipt, a delivery app acquired by Target. Like Salgado, many workers who have been furloughed, laid off or can’t work from home are rushing into the gig economy, lured by the promise of an immediate and flexible way to earn money.

This massive influx of new gig workers could become a more permanent fixture of the economy if consumer demand for home delivery stays strong after the pandemic or if tech companies normalize replacing employees with gig jobs. That means more Americans could face the same inequities exposed by the virus, such as access to health care and sick leave.

Even in the best of times, gig work offered few protections. But the virus crisis has increased the stakes of operating without a safety net. Most on-demand companies offset thin profit margins by offloading the risk onto workers, who are classified as independent contractors and have to provide their own vehicle and gas. There is a lack of basic employee protections. Take-home pay is volatile, and there is no minimum wage or overtime.

“It’s one of the most vivid illustrations of how work has become more precarious,” said Molly Kinder, a fellow at the Brookings Institution, a public-policy think tank. “In a moment where we are all feeling vulnerable — about our jobs, our family and our health — it makes us think: Is this really what we want the work of the future to be?”

State and local officials have now deemed these workers essential, but companies continue to treat them as replaceable. Workers say packages of face masks and hand sanitizer have arrived delayed or damaged. DoorDash charges drivers up to $5 per shipment of face masks and hand sanitizer. Instacart told Salgado on April 11 that his safety gear was in the mail, but he still hasn’t received it. In response to questions from The Washington Post, Instacart said the kit was still in transit and the company would expedite a new one to Salgado. DoorDash declined to comment.

There were 1.6 million gig workers in the United States in 2017, according to the most recent survey from the Bureau of Labor Statistics. Surveys conducted around that time by McKinsey Global Institute and the Freelancers’ Union found that 25 to 30 percent of all U.S. workers engaged in nontraditional or gig work, as either a primary or supplementary income.

Silicon Valley, led by Uber and Lyft, spent a decade pitching this labor arrangement as both empowering and inevitable.

But, illustrating the volatility of gig work, Uber’s ride-hailing business has fallen by 80 percent during the coronavirus crisis, CEO Dara Khosrowshahi said during an earnings call this month — meaning many fewer rides for its drivers. Forty percent of the app’s drivers in the United States and Canada were cross-dispatched in April to Uber Eats.

Despite a rising number of covid-19 cases among workers at grocery stores and Amazon warehouses, the companies have filled the majority of their new positions.

Instacart, founded in 2012, more than doubled its workforce in two months, thanks in part to Facebook ads with the coronavirus-sensitive slogan “Make money without passengers.” Target’s Shipt brought on 100,000 workers, doubling the size of its fleet in two months after six years in business. DoorDash launched a program to quickly approve furloughed restaurant workers for gig jobs on its platform. And Amazon has seen more new drivers sign up for Amazon Flex, a gig service where workers use their own vehicles to deliver packages or groceries from Whole Foods, said spokeswoman Rena Lunak. (Amazon CEO Jeff Bezos owns The Washington Post.)

In interviews with 20 people who signed up for these jobs since the coronavirus crisis hit two months ago, workers said the barrier to entry was low, requiring little more than a background check, driver’s license and car insurance. But many found a steep learning curve in navigating company policies that shape pay and hours. Nearly all recruits said the availability of work and pay dropped off after a few weeks. In online forums, workers blame the drop on bots or the deluge of new workers.

Instacart said its gig workers, known as shoppers, “appreciate the choice and flexibility that shopping on the Instacart platform affords them,” according to spokeswoman Natalia Montalvo. She added that most shoppers “use Instacart primarily to supplement their income from other forms of work — providing a critical lifeline for people during this economic downturn.”

Shipt spokeswoman Julie Coop said policy changes during the pandemic have benefited workers. “We are committed to our people, and work closely with our independent shoppers to ensure working opportunities that meet their needs,” Coop said.

Max Rettig, head of public policy for DoorDash, said, “We will continue to do everything we can to promote the health and safety of those we serve through our platform while providing meaningful, flexible earning opportunities during this time of economic crisis.” He added that its drivers earned on average more than $23 per hour last month, including tips. Lunak said Amazon Flex offers workers an opportunity to set their own schedule and that, on average, workers drive 13 hours per week and earn more than $25 an hour.

Lawmakers have expanded benefits like unemployment to gig workers in recent months, despite the fact that companies have not paid into state unemployment funds. (In some states, income from gig apps can reduce the amount of unemployment workers are able to collect, but laws vary.)

In May, California sued Uber and Lyft for denying workers minimum wage, overtime and sick leave, in violation of a state law that went into effect in January, but companies say it does not apply. “Sometimes it takes a pandemic to shake us into realizing what that really means and who suffers the consequences,” California Attorney General Xavier Becerra said during a news conference announcing the lawsuit.

In the meantime, the flood of new gig workers has become the most high-stakes test of flexibility versus precarity.

“A lot of them don’t know how to schedule themselves, navigate through the app or see their earnings,” said Nicholas Trinidad, who has been working for DoorDash and other delivery apps for two years and fields questions from recruits while waiting in restaurant parking lots or at the grocery store.

Many recruits are learning by doing. Debbie Everitt Welker has worked as a hair stylist in Texas since 1984 but found herself temporarily out of a job when the Dallas salon where she cuts hair had to close to comply with shelter-in-place orders. Welker signed up for Instacart after an ad popped up on Facebook promising up to $25 per hour. Grocery shopping sounded simple enough. After all, she’d been doing it for decades.

Welker knew she would still have to deduct money for gas, taxes, and wear and tear on her car, but she figured even $15 an hour was worth her time. “I never imagined it would be under $10 an hour,” she said.

Instacart’s algorithm organizes grocery orders into “batches,” which can include up to three different customers. Workers then select gigs from a Twitter-like feed, which shows earnings per batch in one lump sum, including tips.

Welker soon discovered that customer tips are reduced when items are not in stock, an inevitable occurrence during a pandemic. “I thought when you accepted a batch, that was what you made,” she said.

The reliance on tips also hurt Salgado, the restaurant worker in Chicago. For a while, he made $150 a day for five or six hours of work, slightly more per hour than he made during shifts at the restaurant. But he also had a customer who lowered his tip from 53 percent to zero after the groceries were delivered, a practice known as tip-baiting, where customers offer a high tip to try to snatch a delivery slot and then claw it back. Instacart allows customers to increase or decrease their tip up to three days after an order is complete.

“I’m grabbing all these groceries that other people have touched,” Salgado said. “I’m still putting myself at risk just for them to take the money back?”

Some recruits who opted for gig work because of the flexibility found themselves devoting unpaid hours refreshing the app to find work — especially after the number of gigs seemed to drop off after a few weeks.

Kelly, a former corporate marketing consultant, has been flipping houses in Pittsburgh since 2018. But in mid-March, the real estate market essentially shut down after city inspectors and appraisers were sent home. Kelly, who declined to give her last name out of fear of retaliation from Amazon, signed up for Amazon Flex because she wanted to work only two or three days a week. But three weeks after starting, the 47-year-old had such a hard time finding orders that for a few weeks she set an alarm for 4 a.m. to grab shifts before they disappeared.

And despite completing all the online video tutorials, she didn’t know that Flex drivers could ask to be compensated if it takes them longer to deliver all the packages than the time Amazon estimates. Amazon calls this an “adjustment,” but “most people out in the real world would call [it] overtime pay,” Kelly said.

When the app is down, it can cost drivers money as well as time. Meredith Troy, who started working for Instacart last month in Oviedo, Fla., said the app crashed just as she had almost finished shopping. Troy was new to gig work after her other three jobs fell through: tutoring and child care — paused during shelter-in-place — and caregiving at an assisted-living facility from which she says she was fired after a disagreement with her manager.

At first when the app crashed, Troy was resigned to losing an hour putting all the items back on the shelves. But when she tried to cancel, a pop-up in the app warned her that too many cancellations could affect her internal ratings. “I was looking at the pork loins in the shopping cart, thinking, ‘Oh, my god, these things are going to go bad, it’s going to reflect badly on me, the customer is going to put in complaints,’ ” she said. So Troy got out her credit card and paid $229.92 herself.

When the app came back online later that day, she explained the ordeal to several service representatives, showing photos of the receipts and screen shots of the customer orders. Troy waited weeks for her full reimbursement, which came through only after The Post asked Instacart about it.

Online forums for workers on Facebook, Reddit and Discord are dotted with stories like Troy’s about getting the runaround from the companies, even when it comes to the two coronavirus-related health benefits promised to most gig workers: free safety gear and paid leave for those with the virus or officially instructed to self-quarantine. Even workers who have been told by a doctor that they contracted the coronavirus, but were not tested, have had trouble accessing health benefits, according to interviews with veteran workers.

Some people who recently signed up for gig work were laid off or furloughed from jobs that didn’t easily cross the digital divide.

Shaylie May, a 22-year-old dance instructor who teaches modern dance, ballet and other classes at a studio in St. George, Utah, is able to do a couple of classes a week on Zoom, but it’s not enough to pay the bills, so she signed up to deliver food for DoorDash in late March. St. George is a resort town without many tourists now, and May can find orders only during peak hours.

When she posted on social media about working for DoorDash, a friend who teaches dance at the same studio called and asked if she was serious. “What’s the other option?” May said she asked her friend. “Either that or I don’t make bills for a couple months.” The friend ended up signing up, too.