At HubSpot, the software company where I worked for almost two years, when you got fired, it was called "graduation".

We all would get a cheery e-mail from the boss saying: "Team, just letting you know that X has graduated and we're all excited to see how she uses her superpowers in her next big adventure."

One day, this happened to a friend of mine. She was 35, had been with the company for four years, and was told without explanation by her 28-year-old manager that she had two weeks to get out. On her last day, that manager organised a farewell party for her.

It was surreal, and cruel, but everyone at HubSpot acted as if this were perfectly normal. We were told we were "rock stars" who were "inspiring people" and "changing the world," but in truth we were disposable.

Many tech companies are proud of this kind of culture. Amazon keeps getting called out for its bruising environment, most notably in a long expose in The New York Times last year.

Mr Jeff Bezos, the founder of Amazon, has said that people who didn't like the company's gruelling environment were free to work elsewhere. "We never claim that our approach is the right one - just that it's ours - and over the last two decades, we've assembled a group of like-minded people," he wrote in a letter to shareholders.

Some viewed the statement as a sign that Mr Bezos at least seems to recognise that it's not normal for employees to cry at their desks. But it was also a defiant message that he had no intention of letting up.

I am old enough to remember the 1980s and early 1990s, when technology executives were obsessed with retaining talent. "Our most important asset walks out the door every night," was the cliche then. No longer.

The average Amazonian - that's really what they call themselves - lasts only about a year at the company, according to a 2013 report by PayScale, a Seattle company that studies compensation data.

Treating workers as if they are widgets to be used up and discarded is a central part of the revised relationship between employers and employees that techies proclaim is an innovation as important as chips and software.

The model originated in Silicon Valley, but it's spreading. Old-guard companies are hiring "growth hackers" and building "incubators", too.

They see Silicon Valley as a model of enlightenment and forward thinking, even though this "new" way of working is actually the oldest game in the world: the exploitation of labour by capital.

HubSpot was founded in 2006 in Cambridge, Massachusetts, and went public in 2014.

It's one of those slick, fast-growing start-ups that are so much in the news these days, with the beanbag chairs and unlimited vacation - a corporate utopia where there is no need for work-life balance because work is life and life is work.

Imagine a frat house mixed with a kindergarten mixed with Scientology, and you have an idea of what it's like.

I joined the company in 2013 after spending 25 years in journalism and getting laid off from a top position at Newsweek.

I thought working at a start-up would be great. The perks! The cool offices!

It turned out I'd joined a digital sweatshop, where people were packed into huge rooms, side by side, at long tables. Instead of hunching over sewing machines, they stared into laptops or barked into headsets, selling software.

Tech workers have no job security. You're serving a "tour of duty" that might last a year or two, according to the founder of LinkedIn, Mr Reid Hoffman, who is the co-author of a book espousing his ideas, The Alliance: Managing Talent In The Networked Age.

Companies burn you out and churn you out when someone better, or cheaper, becomes available. "Your company is not your family," is another line from Mr Hoffman's book.

His ideas trace back to a "culture code" that Netflix published in 2009, declaring: "We're a team, not a family." Netflix views itself as a sports team, always looking to have "stars in every position". In this new model of work, employees are expected to feel complete devotion and loyalty to their companies, even while the boss feels no such obligation in return.

Unfortunately, working at a start-up all too often involves getting bossed around by undertrained (or untrained) managers and fired on a whim. Bias based on age, race and gender is rampant, as is sexual harassment. The free snacks are nice, but you also must tolerate having your head stuffed with silly jargon and ideology about being on a mission to change the world.

Companies sell shares to the public while still losing money. Wealth is generated, but most of the loot goes to a handful of people at the top, the founders and venture capital investors.

The Netflix code has been emulated by countless other firms, including HubSpot, which employed a metric called VORP, or value over replacement player. This brutal idea comes from the world of baseball, where it is used to set prices on players.

At HubSpot, we got a VORP score in our annual reviews. It was supposed to feel scientific, part of being a "data-driven organisation", as management called it.

Our offices were in a renovated 19th-century factory built by the furniture maker A.H. Davenport. Cavernous redbrick rooms where skilled craftsmen once laboured on elaborately hand-carved custom pieces - woodworking treasures that today can be found in museums and in the White House - were now packed with young people who spent long days cold-calling prospects, racing to meet tough monthly quotas, with algorithms measuring their productivity. The "business development representatives", who were really glorified telemarketers, were paid around US$3,000 (S$4,000) a month, which works out to US$18.75 per hour, if you work 40 hours a week, though many worked more.

Grinding out phone calls, trying to make a number, hooked to a machine that watches you work - this is progress?

The people who worked in the furniture factory likely didn't have easy lives, either. They certainly didn't have a beer garden, as workers at HubSpot do.

On the other hand, they didn't go through weeks of training that felt eerily like a cult indoctrination, being told that they could use their "superpowers" to "change people's lives" by spreading "delightion" to their customers.

Given the choice, I think I'd rather make furniture.

NEW YORK TIMES

•Dan Lyons is the author of Disrupted: My Misadventure In The Start-Up Bubble.