See the 'Stranger Things' Kids' Adorable Audition Tapes Ahead of the Series' 2016 Premiere

The young cast of Stranger Things is all grown up.

But before the hit Netflix series premiered in July 2016, they were still just kids and had to go through an audition process like any other.

As the show's casting director Carmen Cuba says in a new video interview for Vanity Fair — which also includes clips from the adorable audition tapes of the likes of Millie Bobby Brown, Finn Wolfhard, Caleb McLaughlin, Gaten Matarazzo and Noah Schnapp — the kids, though young, were already experienced in the world of acting.

"Very early on, the [Duffer Brothers] and I discussed that these parts were not likely gonna be able to be pulled off by a kid who didn't have some experience," said Cuba.

"So while some of my process involves being out in the world and seeing a kid that looks a certain way and talking to his parents and saying, 'Hey, does your kid wanna act?', this was not gonna be that, because it was going to be such hard work," she continued. "It was gonna be every day, for months on end, and very specific dialogue."

"So that was helpful because from the very beginning we were like, 'Okay, no street casting for this. We're gonna start with theater schools, acting coaches, kids who've been on Broadway," Cuba explained. "The kids in the Stranger Things cast have not popped up out of nowhere — they'd been working really hard for years prior to us finding them."

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Cuba went on to recall details about the auditions from Brown, now 18, Wolfhard, now 19, McLaughlin, now 20, Matarazzo, now 19, and Schnapp, now 17, who would all skyrocket to fame as a result of their roles on the sci-fi drama series.

Brown, who plays Eleven/Jane and was 11 at the time of her tryout, wowed the casting crew with her emotion in a crying scene during her audition — and the British actress even kept an American accent throughout her audition process, which Cuba said was an "impressive" feat.

Wolfhard, who plays Mike Wheeler, was "super sick" during his audition on tape. But according to Cuba, "none of that showed."

"You could tell he had energy and life and was really excited to play the part," she added. "And had sort of the same adventurous, playful spirit as his character. So that was very memorable."

Of the "fantastic" McLaughlin, who plays Lucas Sinclair, Cuba said, "He's somebody who'd been on Broadway, we knew he had experience, and he brought an energy that the other kids fed into. All of them together have a very distinct energy and personality that create this friend group, and we saw that immediately from his very first audition."

Stranger Things sees Brown, Wolfhard, McLaughlin, Matarazzo and Schnapp acting alongside several other kid and adult cast members as they continue to fight various Upside Down-related Big Bads throughout the series, set in the fictional town of Hawkins, Indiana. It has been nominated for a total of 51 Emmy Awards, winning seven.

Following the release of season 4, part 2 on July 1, Stranger Things' upcoming fifth season will be its last.

The show's creators Matt and Ross Duffer announced the beginning of the end in February when they revealed that the "supersized" season 4 would be the penultimate installment.

"Seven years ago, we planned out the complete story arc for Stranger Things. At the time, we predicted the story would last four to five seasons," they wrote at the time.

Added the pair, "It proved too large to tell in four, but — as you'll soon see for yourselves — we are now hurling toward our finale."