The many millions of people heading home for Spring Festival each year make China the scene of the world's largest annual human migration.

While that's good news for transport operators and travel agents, other sectors face the challenge of finding temporary workers over the holiday to replace those on the move.

It's a problem one woman in Shanghai grappled with before this year's Spring Festival holiday, sending multiple recruitment notices to friends and neighbors on the WeChat social media platform looking for someone to step in as a caregiver for her frail, elderly parents.

She said she had been mentally prepared for the Spring Festival "nanny shortage" and had tried to make reservations for a temporary live-in caregiver with several domestic services agencies. But they failed to respond to her requests.

The lingering effects of the COVID-19 pandemic meant her parents' regular caregiver did not return home last year, and she asked for a longer period of leave this year as a result.

"My parents are in their 90s, have serious underlying diseases and show signs of dementia," the Shanghai resident, surnamed Chu, said, adding that she also had to keep an eye on her grandson during his winter holiday.