NEW YORK (BLOOMBERG) - Coinbase Global was seen as a gateway to a promising career in cryptocurrencies. Now would-be hires who have had their offers rescinded are racing to make alternative arrangements after the company's abrupt halt on expanding its ranks.

A computer science graduate in Illinois regrets giving up his PhD offer. A slew of foreign workers are facing deadlines to find sponsors for their work visas. Some are even rethinking the decision to join the crypto industry after experiencing its brutal boom-and-bust cycles first-hand.

Many were caught flat-footed last week when they received an e-mail from the largest United States cryptocurrency exchange rescinding offers and announcing a freeze on hiring for the "foreseeable future".

In a blog post, Coinbase's chief people officer L.J Brock said that while the company did not "make this decision lightly", it is the prudent one given market conditions.

Coinbase declined to share the total number of offers rescinded.

However, a job portal set up by the company for affected candidates had more than 330 people signed up within the first day of launch.

"I got laid off even before I got a chance to prove myself," said Mr Conner Hein, 22, who graduated from University of Michigan in May. He accepted an offer from Coinbase in February, after which he said he turned down offers from PricewaterhouseCoopers and Amazon.com.

Drawn by Coinbase's remote-first policy, he has been city-shopping between Chicago and Austin. A self-proclaimed "hesitant" crypto believer who sees promise in the technology but dislikes its get-quick-rich schemes, Mr Hein said he would now "look twice" if a prospective employer is related to blockchain or cryptocurrencies.

Coinbase management failed to plan the runway accordingly, making promises that it was not ready to keep, he added.

"I've always had my hesitations," he said. "I just didn't think the crypto industry would drop this hard."

Along with the plunge in crypto prices, shares of Coinbase have gone from one of the stock market's most hotly anticipated debuts to one of its most spectacular crashes in a little more than a year.

The company ballooned to 4,948 full-time employees, from about 1,700 just a year ago. But now, its hiring freeze comes after broad crypto-market declines and subsequent doldrums have led other firms such as Gemini Trust and Mercado Bitcoin's owner to cut jobs.

The situation is even more dire for would-be hires reliant on work visas, which make up a sizable amount of the talent pool for technology jobs in the US.

Mr Ashutosh Ukey, 23, moved to the US from India when he was eight years old. He now has about 150 days to find a job that would sponsor a visa. When searching for jobs, he was deciding between offers from Coinbase and a computer science doctorate programme at the University of Illinois Urbana-Champaign.

"I was curious and interested in learning about crypto, and learning from one of the biggest players was a one-of-a-kind opportunity," he said.

For Mr Ukey, a job at Coinbase meant not only a ticket to join the next big tech firm, but also a chance to get an employment-based visa. "I would say my experience with Coinbase strayed me away from working in crypto," said Mr Ukey. "In the immediate future, I am looking into more long-established tech firms."

On LinkedIn, posts by similarly situated international job candidates are being widely shared. In response, Mr Brock said on Twitter: "We acknowledge this is a particularly difficult situation for those looking to either enter or stay in the US on work-related visas."

In addition to the severance packages and job-seeking support, the company is providing legal services to those with visa issues, he added.

A hiring freeze could spell further trouble for growth at Coinbase, especially when it comes to global expansion. In April, chief executive Brian Armstrong announced a major hiring plan at its technology hub in India, tripling the headcount to about 1,000 within the year.

Mr Gaurav Rawal, 24, a software engineer from Bengaluru, was to join Coinbase in India. He has resigned from his previous job, but days before his start date, his offer was rescinded. The recruiter had just recently assured him of his start date.

"Even he was clueless," Mr Rawal said in an interview of the recruiter. "The whole Indian team was clueless on what's happened."