• CNBC interviewed 10 current and former employees of Chinese tech firms to ask what work life is like in those companies' Singapore offices.
• The hours may sometimes go long, but most people who spoke to CNBC said the "996" work culture common among tech firms in China hasn't been adopted in Singapore.
• English-speaking workers described Mandarin being common in the workplace, as well as working on contract.

While interviewing for a job at Chinese tech giant Tencent, a now-former employee asked if he would be expected to use Mandarin at work in the Singapore office.

He was satisfied with the answer that a mix of Mandarin and English would be required. He accepted the position.

But the reality was different — Mandarin was used in the office very frequently, the former employee said. The man, a Singaporean, ended up leaving Tencent because of difficulty communicating.

"If I need to spend so much time trying to understand things, I'm going to be very inefficient," he said, adding that a person who's better with Mandarin "is probably a better fit."

Working at a Chinese tech firm

Chinese tech companies are expanding their offices around the world, including in Southeast Asia.

As they post openings overseas, more people are wondering what it's like to work for them. This year, CNBC reported on tech workers in the United Kingdom who turned down job offers at TikTok, which is owned by China's ByteDance, after encountering stories about an intense work environment there.

Those people cited fears of the so-called "996" work culture practiced by some companies in China, which requires employees to work from 9 a.m. to 9 p.m., six days a week. A TikTok spokesperson told CNBC in May of this year that "we absolutely do not have '996′ policies."

CNBC interviewed 10 current and former employees of Chinese tech firms to ask what work life is like in those companies' Singapore offices. Most requested anonymity owing to fear of repercussions or because they do not have permission to speak to the media.

Their stories varied a great deal according to the company, the role and the individual.

Four former or current Huawei employees told CNBC that colleagues from China often napped in the office during lunch breaks, as is common in Chinese office culture. Now that people mostly work from home, two of them said, employees log on to a video call every morning. They said they believe the purpose of the call is so they can show that they are ready for work at 9 a.m. and to discuss plans for the day. They added that their managers take a screen shot of everyone in the call.

But individuals who spoke to CNBC didn't exclusively describe work cultures that are rigid or difficult. Three people who have worked at ByteDance or Tencent described a hierarchy at those companies that was "flat," with little emphasis on titles or positions. One ByteDance employee said he can speak to a vice president in the company freely, something he doesn't think is typical at other firms.

ByteDance declined to comment for this report.

But three things came up repeatedly in conversations with workers and former workers from Huawei, Tencent and one Tencent subsidiary: a heavy reliance on Mandarin, the use of fixed-term contracts, and work outside normal business hours.

Speaking Mandarin

The hiring process at Tencent took place in English, but almost "everything" else was in Mandarin at Tencent's Singapore office, according to the former employee who left the company because of the language barrier.

Even documents essential to his work were in Mandarin, and his command of the language is "average," he told CNBC.

More than 74% of Singapore's population is ethnically Chinese, but most major businesses in Singapore operate in English.

The individual pointed out that Tencent's presence in Singapore is "quite new," and he speculated that the company may not have had time to "localize" yet. The gaming and social media company announced its plans to open a regional hub in Singapore only last year.

As was the case with difficulties in work culture, difficulties with language weren't reported by all the employees and former employees who spoke to CNBC. Some said they had encountered no problems.

"If you prefer English, [colleagues from China] can speak in English too," said a current Huawei employee. "We try to meet in the middle."

The current ByteDance employee who described the company's hierarchy as "flat" said that when it comes to language, there's "no barrier," since colleagues in China can speak English.

Tencent recently announced internally that it intends to shift toward using English in the international team, said one employee. She said she expects that move to take time, because most of the systems and documents are currently in Mandarin.

Patricia Teo, executive director of technology practice at recruitment company Kerry Consulting, said much of the day-to-day work at Chinese tech firms is likely to involve heavy interaction with China-based teams.

"It is not a nice-to-have to be able to work in Mandarin fluently," she said, "it is actually a necessity."

Meetings, training and conversations with tech or finance staff all took place in Mandarin at one Tencent subsidiary, another former employee said, describing the situation as "overwhelming." Tencent did not address this claim when reached by CNBC for comment.

"Everything was in Chinese," she said.

"It's quite stressful, especially when you need to get a point across and your shoddy [Mandarin] cannot get it across," she added.

Jun, a former Huawei intern who wanted to be identified by one name, said that even if he sent English emails or text messages to his colleagues, replies tended to be in Mandarin. He interned at the company in 2017.

Fixed-term contracts

Multiple people who spoke to CNBC said it's common for Singaporeans to be hired at Chinese firms on contracts of one to three years, though Kerry Consulting's Teo said most roles in Singapore are permanent because there's a shortage of candidates.

The former Tencent employee who left because of the heavy use of Mandarin said he was on a contract, with a chance of converting to a permanent role after a year. But he said he was not confident that the company would offer him a permanent role.

A former Huawei employee, Ong Xuan Jie, said he wasn't offered a permanent role after a year in the company, but he said he believes that was because the company had already hit a cap it set on permanent slots.

Ong added that the contract situation at Huawei didn't seem out of line with the industry. Still, he wanted more stability since he was just starting out in his career at the time. He left the company in 2018.

When contacted by CNBC, Tencent and Huawei declined to comment on contract roles.

The employee at Tencent who said the company is trying to shift toward using English said she preferred a contract role, as it would give her the flexibility to move on if the job wasn't a good fit.

Matthew Durham, a lawyer with experience handling employment matters in mainland China, said fixed-term contracts are common there for new hires. That's because — unlike in Singapore — employment law in China allows employers to terminate contracts only under specific, limited grounds, he said.

In China, poor performance by an employee is generally not a valid reason for termination unless it can be shown to constitute incompetence, said Durham, who works for Hong Kong law firm Gall.

"Employers can use a fixed-term contract to ensure that they have a guaranteed 'out' after a certain period, so that they are not 'locked in' to contracts," he said, adding that companies have to sign an open-term or permanent contract after two fixed-term contracts with an employee.

At some companies, employees said there was little difference between workers on fixed-term contracts and those in permanent roles. But at Huawei, permanent staff and contract workers are entitled to two different sets of employee referral benefits — the bonus they get for referring a new employee to the company.

According to information provided by the employee who said Mandarin-speaking colleagues can switch to English if needed, Huawei's contract staff and permanent staff get similar referral bonuses for helping to fill more junior roles. But for more senior roles, there's a disparity: A permanent staff member who successfully refers someone to a senior position can get a bonus that's three times the incentive a contract employee will get for the same referral.

Durham, the lawyer from Gall, said employees on fixed-term and open-term contracts within China usually have the same benefits.

However, some firms may offer better bonuses or entitlements to open-term contract employees, who likely have a longer track record in the company, he said.

'No real rest time'

Singaporeans who have worked at Chinese tech firms said job-seekers should be prepared to work long hours, especially when interacting with colleagues based in China.

"There is no sacred day or time," said the former employee who found the use of Mandarin at a Tencent subsidiary overwhelming. She said her bosses, who are based in China, sent her questions at night, during the weekend and on public holidays.

"You could just ignore it, but would you really be able to relax knowing your boss is waiting for your reply?" she asked.

"There's no real rest time, only work time and standby time," she added.

Ang, a former employee at the same Tencent subsidiary who asked to be identified by his last name, said co-workers in China tended to put in extra hours to make up, in advance, for lost time before the Lunar New Year and Golden Week holidays. Colleagues would contact him during the weekend, he said.

"You will feel like you're working double, but you're not getting any leave," he said.

However, not everyone reported inordinately long hours.

"There are definitely teams that work a little later, but I wouldn't think anyone is forced to work outside of what the standard timings are," said the ByteDance employee who said the company's hierarchy is "flat." A colleague who also spoke to CNBC echoed his sentiments on work-life balance.

'996' culture in Singapore? Not really

The hours may sometimes go long, but most people interviewed for this article said China's '996' work culture has not been adopted in Singapore. Some said they believe their hours are in line with those of other companies.

Kerry Consulting's Teo said Chinese companies are taking steps to improve work-life balance because '996' culture has been the "main deterrent" for potential employees in Singapore.

"As a fast-paced global technology company, we know that striking a healthy work/life balance is critical for employees to do their best work," a Tencent spokesperson told CNBC in an email.

"We strive to offer a unique working environment that balances the energy of a start-up with the resources of a global innovation leader and will continue working with employees to develop a career path and work/life balance that is suitable for each individual," the spokesperson said.

People work outside office hours in "most jobs" in Singapore, said the employee who told CNBC that Tencent is trying to shift toward using English. Her managers have been telling her to knock off at 6 p.m., she said.

The former Tencent employee who left the firm because of the heavy use of Mandarin reported working hours beyond his contractual obligations when he was there, "occasionally maybe 9 a.m. to 9 p.m. But definitely not Saturday. It's like, '995.'"

—CNBC's Sam Shead contributed to this report