The tough working conditions allegedly facing Amazon employees have made headlines for years now — and it seems it's been the case from day one.

Amazon's first ever job ad — listed by founder Jeff Bezos in 1994 — was unearthed last year by BNN Bloomberg host Jon Erlichman, and shared on Twitter.

And 12 words buried within the ad could be the secret to the company's phenomenal success — although it also paints a grim picture about the tech giant's stringent standards.

The ad was for software developers for a company called Cadabra, as Amazon was then known as, and was posted to a public message board, news.com.au reported.

"Well-capitalised start-up seeks extremely talented C/C++/Unix developers to help pioneer commerce on the internet," the message reads.

"You must have experience designing and building large and complex (yet maintainable) systems, and you should be able to do so in about one-third the time that most competent people think possible.

"You should have a BS, MS, or PhD in Computer Science or the equivalent. Top-notch communication skills are essential. Familiarity with web servers and HTML would be helpful but is not necessary.

On this day in 1994: Jeff Bezos posts the first job ad for Amazon pic.twitter.com/5ysOWB5OZ6

— Jon Erlichman (@JonErlichman) August 22, 2018

"Expect talented, motivated, intense, and interesting co-workers. Must be willing to relocate to the Seattle area (we will help cover moving costs). Your compensation will include meaningful equity ownership."

Mr Erlichman's tweet went viral at the time, with social media users describing the requirement to perform tasks "in about one-third the time that most competent people think possible" as "disgusting", "ridiculous" and "unrealistic".

"Should be able to do in one-third of time? Looks more like a slave search than employee," one Twitter user wrote, while another added: "So everyone is just going to skip over 'one-third the time that most competent people think possible'? #Start-up translation: you working 80 hrs/week."

Amazon's first job ad reveals company's dark side. Photo / Google

Amazon turned 25 on Friday, and the job ad is now doing the rounds on social media again as a result of that milestone.

The online retail giant has achieved remarkable growth in that time, becoming the world's most valuable public company in January this year and cementing Mr Bezos as the world's richest person, with a $US131 billion fortune.

However, Amazon has also gained notoriety for all the wrong reasons over the years.

Last year, undercover investigator James Bloodworth claimed Amazon warehouse staff in the UK were peeing in bottles in lieu of a bathroom break to avoid taking too long away from the job, while a different undercover investigation by UK reporter Alan Selby revealed warehouse workers unable to handle the strain of punishing quotas were regularly taken away by ambulance.

And in December 2018, it was revealed Melbourne mother Rachel Shafner was seeking $274,815 in compensation from Amazon after claiming she was fired for asking to pick her kids up from school.

According to The Sydney Morning Herald, Ms Shafner claimed she was let go after asking for a flexible working arrangement last August which would have allowed her to leave the office at 3pm and continue working from home after picking up her children from school and childcare.

The mum-of-two asked for the new arrangement as her husband had fallen ill in March, which meant he was in and out of hospital.

However, an Amazon spokeswoman denied the allegations when contacted by news.com.au.

Meanwhile, Mr Bezos' personal life has also been under the spotlight recently following his split from wife MacKenzie.

Ms Bezos received nearly $55 billion this month, making it the world's biggest divorce settlement in history.