“I feel like I’m in a fairy tale,” Sean Wang told the crowd gathered at the Ray Theater in Park City, Utah, last month for his Sundance Film Festival debut.

Wang, a 29-year-old filmmaker, wore a black suit and white Vans (a nod to his skateboarding roots). He grabbed his chest to show how fast his heart was beating while presenting his movie, “Dìdi.” It’s a coming-of-age story about a distraught and insecure 13-year-old Taiwanese American boy trying to find his place in the world.

“I’m going to take a few seconds to take this all in,” he said before taking a photo of the audience. The warm crowd included Mr. Wang’s family and friends, the film’s cast and crew, and a handful of potential buyers who have the power to transform his position in life from aspiring filmmaker to bonafide Hollywood director.

It has happened before. Luminaries like Steven Soderbergh, Quentin Tarantino, Damien Chazelle, Ava DuVernay and Lulu Wang went from hopeful dreamers to actual filmmakers, thanks in part to the Sundance Film Festival, which just wrapped up its 40th year.

Mr. Wang is familiar with that lineage, and has apparently been preparing for his Sundance moment since discovering the work of Spike Jonze. skater videos as a teenager before going to film school at the University of Southern California. While working intermittently for Google Creative Lab, he made a series of short film that undermined different aspects of his childhood.

She also participated in multiple Sundance programs, including one for filmmakers ages 18 to 25, a screenwriters’ lab, and a directors’ lab. Each of them helped him hone his script, a personal film that honors his relationship with his mother and reimagines teen movies like “Stand By Me” and “Eighth Grade” through the lens of a first-generation American growing up. in the cultural melting pot that was Fremont, California, in 2008. (Dìdi means little brother in Mandarin and a term of endearment in Chinese culture.)

Now, after working hard on her script for six years and finishing the film, Wang is taking her first steps into the spotlight thanks to Sundance. The moment coincided with the promotion of her short film, “Nai Nai & Wài Pó”, about her two grandmothers. That film was recently nominated for an Oscar in the documentary short category and will soon be available on Disney+.

“It’s almost too much to fully process,” he said in an interview. “It’s really exciting, really surreal, definitely stressful, but overall I feel good.”

Wang has already overcome some unlikely difficulties. Her film was chosen from a group of more than 4,000 candidates. And it landed in Sundance’s U.S. drama competition, a category that has produced a slew of Oscar contenders, including “CODA” and “Minari.”

However, before a movie can be an awards season contender (or even a movie that general moviegoers can see) it needs to find a buyer. And that’s what Mr. Wang expected at Sundance.

At a panel featuring new filmmakers, Mr. Wang commiserated with other newcomers who were about to present their films. Instead of talking business, the directors focused on how they hoped audiences would react and how they had gotten their films made, many of them baffled that it was happening.

“I will get emotional if I talk too much,” Wang said when asked about the people who were by his side during the filming process. “I’m trying not to cry more than 10 times at this festival.”

Behind all that gratitude, though, was a mild anxiety: Would audiences and critics like the film? Would that be enough for a buyer to purchase it and plan to distribute it?

Before the film’s release, Wang and his producers locked themselves in a makeshift green room. “Dìdi” features a handful of new actors alongside more seasoned veterans like Izaac Wang (“Good Boys”), who plays Didi, and Joan Chen (“The Last Emperor”), who plays her mother. The team decided not to screen the film to any buyers in advance.

“We really want to honor this experience and let the film speak for itself,” said producer Carlos López Estrada.

It was a decision that increased the pressure of the moment and somehow preserved the feel of the film that Wang was desperate to protect.

“This movie should feel community-driven, like it came from the ground up and not like Hollywood came to my hometown,” he said. “We did it successfully. “My grandmother could be in a movie with this ageless actress, and it all seems like the same world because we kept it at home.”

The reception at the end of the film was raucous. The crowd gave the film an enthusiastic standing ovation and Mr. Wang once again wiped away tears as he absorbed it all.

Michelle Satter, founding director of the Sundance Institute, was part of the crowd, cheering on her budding filmmaker as she did notable directors like Ryan Coogler (“Black Panther”) and Chloé Zhao (“Nomadland”), who passed on from Sundance . to the Oscars. Wang attended his directing lab just weeks before beginning production on “Dìdi,” using the mountainous setting of Utah to test his two most complicated scenes.

“Sean is going to have an incredible career and we totally believe in him,” Satter said before Wang took her away to meet his family.

“Thank you for supporting Sean,” Cynthia Lee, Mr. Wang’s mother, tearfully told Ms. Satter. “As a mother, I appreciate you.”

The criticism began to pour in as the filmmaking team headed to the after-party. The Hollywood Reporter called “Dìdi” “moving,” while Variety called it “fresh and funny.” IndieWire wrote that it evoked “a sense of time, place and texture that distinguishes this fun, fleeting film from the pack of coming-of-age films at the Sundance Film Festival.”

The party was a lavish affair filled with Asian cuisine from caterer Mama’s Night Market. The band Hellogoodbye, which stars in the film, played at the party, and Mr. Wang’s childhood bedroom, which was used in the film, was recreated in the venue’s lobby. The place was full and guests were turned away. Mr. Wang was mobbed by excited admirers and colleagues. Outside of Park City, he’s still an unknown. But that night, inside that room, he was a superstar.

“The discoveries coming to Sundance this year look a lot like some of the really exciting discoveries from filmmakers and films of the last 20 years,” said Tom Quinn, CEO of distributor Neon. “’Didi’ fits that. It heralds the dawn of this incredible new filmmaker.”

Adding to the whirlwind of enthusiasm was Mr. Wang’s Oscar nomination for his documentary about his grandmothers. He flew back from Utah to watch the nominations announcement early in the morning. with his family in his childhood home. When “Nai Nai & Wài Pó” was announced as the final nominee in the short film category, Mr. Wang buried his head in his grandmother’s lap and then fell to the floor.

“I’ll never get used to this,” he later said in an interview.

“Dìdi” ended up winning the prestigious Sundance Audience Award, an award that in years past went to films like “CODA” and “Whiplash.”

On Wednesday, Mr. Wang was back at his apartment in Los Angeles. The sun was shining and he was sporting a new haircut when Focus Features announced the purchase of worldwide rights to “Dìdi,” which will likely be released in theaters this summer, perhaps as an antidote to the blockbusters that typically consume theaters. at that moment.

It was the end of a whirlwind adventure that many aspiring filmmakers can only dream of.

“There is something about being in Park City, where all the things that were happening to me didn’t seem real,” Mr. Wang said. “You are in this place like a snowball and my attention was needed in many places, every second of every day. Coming back and then being in the news, I feel like, ‘Oh wow, we really did that.'”

Audio produced by Tally Abecassis.