CHICAGO • Mr Brandon Williams arrived at an Amazon fulfilment centre outside Chicago at about 7.30am one recent Wednesday, one of thousands across the United States who turned up for the company's first Jobs Day.
While he appeared to wilt slightly during the five hours he waited before being summoned for a tour, his enthusiasm did not wane.
"What's not great about a company that keeps building?" he said.
The event was a vivid illustration of the ascendance of Amazon, the online retail company that, to a far greater extent than others in the tech industry, has a seemingly insatiable need for human labour to cope with growth.
It recently expanded its Prime Now service to Singapore, but did not have enough deliverymen to fulfil the flood of orders within the promised two hours.
In the US, Amazon needs armies of people, too, to pick and pack orders in warehouses. Its Jobs Day, held at a dozen locations, was intended to help fill 50,000 of those positions, 40,000 of them full time.
Those lower-paid jobs did not seem to bother the attendees, many of them united in the conviction that there was an opportunity to move up the career ladder to, say, a job in information technology, marketing or even fashion.
Amazon's warehouse jobs, which typically pay US$12 (S$16) to US$15 an hour, have a reputation as being physically demanding and repetitive, with high rates of burnout.
It has successfully resisted union organising that might introduce more worker protections.
But the company has said its wages and benefits are attractive.
Five years ago, it introduced a programme called Career Choice that pays tuition costs for employees seeking training to join higher-paid professions, such as airline mechanics, medical laboratory workers and computer-aided design technicians.
It is indisputable that the growth of e-commerce, which Amazon captures a big chunk of, has devastated many physical retailers, leading to store closures and lay-offs.
However, Amazon's remarkable headcount growth stands in sharp contrast to its image as a job killer.
It was the fastest US company in history to employ 300,000 people globally, crossing that threshold last year, its 20th as a public company, according to a paper published this year by the Progressive Policy Institute, a think-tank.
US retailer Walmart reached that milestone 21 years after it went public, the paper noted.
Amazon now has more than 382,000 employees globally.
The figures do not include the thousands of seasonal workers who join the company to help it with the crush of holiday shopping.
Facebook, in contrast, employed just under 21,000 people at the end of June. Alphabet, the parent company of Google, employed about 76,000.
Professor Arun Sundararajan, of information, operations and management sciences at New York University, said Amazon's employment needs are unique among tech companies.
"Its business has always been a meld of the digital and physical. Retail is very different from digital products, music or social networking. The other tech platforms are, at their core, selling tech products."
But there are questions about how long Amazon's warehouse jobs will exist as robots become more capable at doing the work that now requires humans.
Many researchers and start-ups are working on robots that have the dexterity to pick orders automatically. Amazon sponsors a competition to encourage engineers to build more advanced warehouse robots.
When those technologies are perfected, the employment picture inside Amazon's warehouses could look very different. That day could be a decade or more away, though.
"While the digital disruption is destroying the traditional retail business model, the Amazon model that replaces it will continue to live in the physical world and require human labour for the foreseeable future," Prof Sundararajan said.
And it will likely have to continue ramping up its hiring - including bolstering its delivery capabilities - if it is to prevent another Prime Now incident, like the one in Singapore, as it continues to expand its global footprint.