Tara Herman, manager of the scheme which launched last November, said the aim of the traineeships was to "bring more diverse voices into the Guardian".
"We wanted to provide [the trainees] with broad exposure to our digital-first journalism, and reciprocally we are benefiting from their diverse experience in digital journalism, from blogging and social media to multimedia, data and coding."
The trainees, who are all aged between 24 and 30 years old, will be editing the features content every day this week with the aim of sharing "Generation Y's perspective on a wide variety of topics and issues".
One of the them is Fred McConnell, who described the opportunity as a "great learning experience".
"We certainly knew from the outset that we wanted to focus on people of our generation and show our perspectives, which is something people aren't necessarily hearing a lot from mainstream media," he said.
"But also we wanted to use that [theme] to bring in a fresher and younger audience than the Guardian is usually able to attract."
Each day will have a particular theme such as media and "bare necessities" for that age-group: food, jobs and housing. Other subjects include sex, international stories and culture.
McConnell admitted it was "an overwhelming workload," with daily deadlines a new experience for most of the team.
"With writing a piece and doing video and keeping on top of social media and all those different roles, because it's a brand new product, we're kind of learning as we go along," he said.
"Luckily we've got the entire [Guardian features] team behind this who would usually be doing this anyway so we're getting a lot of support from the regular editor and production is on hand."
The trainees are essentially commissioning editors for the week but have also produced a lot of the content themselves, including their pick of the "brightest young media stars" under 30, an in-depth look at the jobs crisis among young people and a revealing multimedia Q&A into transgender sex lives.
And McConnell, who was previously a proofreader for an English-language newspaper in Yemen before "trying to survive" as a freelancer in London, says schemes such as this one are "massively important" for aspiring journalists.
"Being on this digital scheme and actually being in this real environment is the best possible place to be."
The digital journalism scheme, which takes on trainees to the Guardian on 12-month paid contracts, runs alongside the Guardian's other training schemes, including the Scott Trust bursaries.
Asked if the Guardian would be running the scheme annually, Herman said this was "still to be confirmed" although she added that the current scheme was "wildly successful, and we're thrilled with the trainees that we've got".