LOS ANGELES — On Saturday evening, over 250 people crowded into a midcentury modern mansion in the Hollywood Hills for a party at the end of LA Tech Week, a six-day event series held across the city.

The party was hosted by House.ai, a collective for entrepreneurs, and Mirra, a telehealth start-up. “We incubate companies, we invest, and we party,” said Robbie Figueroa, 27, one of House.ai’s founders.

Just before sunset, the first wave of guests arrived. A D.J. played soft EDM music by the pool throughout the evening. Dozens of boxes of Domino’s pizza, a packed cooler of Dezo spiked coconut water and a Dippin’ Dots ice cream machine were on hand to keep attendees refreshed.

And who were those attendees? “It’s nerds, including myself, who have been clogged up at home for the past six months letting loose,” Mr. Figueroa said. “Everyone is referring to each other by their Twitter handles.”

Nikil Viswanathan, a founder of Alchemy, a blockchain developer platform that recently raised $80 million, showed up in a sailor suit. (He was attending a theme party afterward.) Austyn J.R Brown, a TikTok star and card game developer with nearly five million followers, and Eric Wei, a founder of Karat, a credit card for influencers, were also there.

There were also more traditional Hollywood types, including a Netflix executive and Arturo Castro, who appeared in the series “Narcos” and “Broad City.” Staffers from Snapchat, TikTok and YouTube mingled as well.

Los Angeles has long had a thriving technology industry. TikTok and Snapchat have headquarters in the city, and many tech executives, including Elon Musk, call it home. But more recently, Gen Z and millennial tech leaders have emerged, building hyped-up start-ups like Dispo, Poparazzi, PearPop and more.

Many moved to the city and established their companies during the pandemic, and LA Tech Week was their first opportunity to gather in person.

It’s not surprising, given who makes up the scene, that the event series came together on Twitter. Kyle Brastrom, 22, an entrepreneur and founder of Dive Chat, a Gen Z group chat platform, moved to the city in May. That month he tweeted: “Hosting a dinner in LA for founders, investors, & start-up folks this Wednesday. Comment or DM if you want to join or tag anyone you think shouldn’t miss this.”

“Quite literally 300 people replied to me,” Mr. Brastrom said, “and I’m like, oh, people in Los Angeles really want to go out. That sparked it all.”

He recruited two of his roommates — Michelle Fang, 22, and Ami Yoshimura, 19 — as organizers. The series was initially planned for May, but the organizers pushed the start date to June 14, the week Los Angeles fully reopened. A week of official and unofficial events — many of which were not advertised until the last minute — led up to Saturday night’s closing party.

“It’s all been in very much Gen Z fashion and embracing the chaos of the situation,” Mr. Brastrom said.

For seven hours on Saturday, guests dressed in brightly colored tops and street wear cycled in and out of the house. One woman had fashioned a dress out of a trash bag. There was not a single Patagonia vest in sight.

The organizers had capped attendance, but people were trying to R.S.V.P. up until the party’s start. Because of the mixed-age crowd, there were wrist bands for those over 21.

While the Silicon Valley tech world is rooted in power and exclusivity, the Los Angeles tech scene is more about creativity and openness. The event embodied a collaborative enthusiasm that runs among young people in Los Angeles. At the party were TikTok stars, start-up founders, direct-to-consumer marketers, songwriters, engineers, college students, livestreamers and artists, all mingling in front of a sparkling view of the city.

“If you believe the creator economy is the future of consumer tech, there’s not a better city than L.A. to be the epicenter of that energy and momentum,” said Jeff Morris Jr., the founder and managing partner of Chapter One Ventures.

Jasmin Johnson, 24, the founder of Knowhere, a travel planning app, said the event exposed her to a different side of tech than she was used to, including meeting TikTok creators. “In some other tech communities folks come from more homogeneous backgrounds, like ‘oh we all attended business school together’ or went to certain Ivys and private schools,” she said. “This is an interesting and cool mix of people with different backgrounds.”

Caitlyn Lubas, 22, a travel content creator, said that Los Angeles has a “totally different energy that I think was really captured through the tech week events.”

Others, too, seemed grateful for the sense of community. Cat Orman, 22, a founder of a drone delivery company, moved to the city during quarantine and was excited to get back to in-person connection. “Now that we’re coming out of that, it’s nice everyone is being conscious of building a community,” she said. “The energy is very good, it doesn’t feel appearance conscious or excessively networky.”

Chris Grant, 29, a product designer who arrived at the party around 9, said he felt like “all of L.A. tech” was there. “Every moment I’m walking around I’m bumping into friends from different circles,” he said. “It’s like, wow, you’re here, too? Sick!” Upstairs, some founders pitched their start-ups in the house’s plush movie theater, a somewhat quiet room isolated from the dance party breaking out below.

Minutes later, snakes arrived. Guests took turns holding the five large reptiles for photos and TikTok videos. Casey Adams, a 20-year-old entrepreneur, allowed one snake to coil around his neck as he gave it a kiss on the top of its head. Mr. Figueroa said he had met the snake handlers at a different party and had asked them to come.

At any given time, clusters of people had their phones out, swapping Instagram handles. “People are collaborative and they’re wanting to come together,” Mr. Brastrom said. “That’s what I love about this city, people are leading with collaboration rather than competition.” Mr. Brastrom has already founded an events studio called Crescendo to recreate experiences like Saturday night.

“It feels like there’s real people here, not just V.C.s,” said Nathan Baschez, 32, a founder of Every, a writer collective start-up. “This isn’t insular. People here aren’t on the lookout for the next interesting thing, they are the next interesting thing.”

Dro Hambarchian, 18, a rising sophomore at U.C.L.A. who is building a movie recommendation app called Script, arrived with two friends from school, Ethan Keshishian, 20, and Arek Der-Sarkissian, 19, founders of Unicorner, a start-up newsletter. “LA Tech Week embodies L.A. and how diverse it is,” Mr. Hambarchian said. “I’m a first-generation American, and I’ve met other immigrants. It’s refreshing.”

Katia Ameri, the Mirra founder, who is from Los Angeles, said she had been waiting for the moment when the Los Angeles tech ecosystem could rival the Bay Area and that now was that time. “We’ve been isolated from each other,” Ms. Ameri, 29, said. “Now we’re all vaccinated and coming out and seeing who’s here.”

By 1 a.m., the party had begun to wind down. Guests waited by the house’s gate, competing for surging Ubers. Some who couldn’t get a ride watched “The Conjuring” in the house’s movie theater. Ms. Ameri assumed D.J. duties and was playing dance music by Dr. Fresch.

Mr. Brastrom, who was still chatting with guests, seemed pleased with the hype he’d created. “I’m a random 22-year-old that came to this city and just said, ‘Let’s do this,’ and everyone just said ‘Yes,’” he said. “And I think that’s insane in the best way.”