Guillaume Lachaud, an android engineer who builds mobile apps for Uber, works on the roof of 20 Mission, a co-living house where he was living at the time, in San Francisco, Calif., in March 2015. Around 45 people live in the building, which is a former single room occupancy hotel that had been vacant for several years before housing the co-living community, which includes many start-up entrepreneurs. Lachaud, originally from France, is one of many young people from all over the world who have come to San Francisco to participate in the economic boom in the technology industry.

Participants in Cal Hacks 2.0, a 36-hour hackathon, work on projects inside the football stadium at the University of California, Berkeley in Berkeley, Calif., in October 2015. According to the event organizers, 2,071 participants attended from 143 schools and 10 countries. Hackathons are events usually lasting a few days in which computer programmers and others involved in software and hardware development collaborate on a project over a set period of time, often while competing for awards and prizes. They’re an important part of the technology industry ecosystem.

At a happy-hour event at Rothenberg Ventures, a venture capital fund that has investments in various virtual reality, drone and artificial intelligence technologies, an attendee tries on a virtual reality headset as others listen to a speaker in another room at the firm’s office in San Francisco, Calif., in July 2015. Rothenberg, which invests in early-stage technology companies with a focus on millennial founders, started River, a virtual reality accelerator program.

Sandy Frank, Mackenzie Hughes and Danielle Gaglioti, seen left to right, work on a start-up called Akimbo inside the apartment that Hughes and Gaglioti were subletting in San Francisco, Calif., in August 2014. The company, described as a “career development platform,” is based in New York, but Hughes and Gaglioti were in town for the summer to participate in Tumml, an urban ventures accelerator program. Frank joined them as an intern. They often worked from home depending on their meeting schedule and available transportation options.

Samidha Visai, center, and Anushree Vora, second from left, dance on a cruise ship while attending an early-morning dance party called Daybreaker in San Francisco, Calif., August 2015. The two university students from Michigan were spending the summer in San Francisco to intern at health technology start-ups. Daybreaker events, which are substance free dance parties held early in the morning on weekdays, are very popular with young technology workers. Attendees often go straight to work from the event, energized by the dancing for the day ahead.

Ben Greenberg, one of the residents of 20 Mission, works in his room at the co-living community in July 2015. The space is a former single-room-occupancy hotel that had been vacant for several years before being turned into the co-living community. Greenberg is a programmer who formally worked at the ridesharing company Lyft and then founded a start-up glowyshit.com where he sells glow-in-the-dark decorations and party supplies.

Mohammed Alkadi, Albara Hakami and Abby Wischnia, seen left to right, host a booth for their company Feelit, a social app to help people express their feelings and emotions, during the Startup and Tech Mixer at the W Hotel in San Francisco, Calif., in March 2015. The networking event, which drew hundreds of people from the tech industry hoping to make connections, was for a time, held every few months.

Guests of a party to celebrate the three-year anniversary of 20 Mission, a co-living house, dance and listen to a DJ playing music using silent disco headphones in the building’s courtyard during the party in San Francisco, Calif., in March 2015. Around 45 people live in the building, many of them start-up entrepreneurs. Impromptu gatherings happen frequently, but the community’s larger parties, which are held every few months, have made the space well known, especially among the start-up community.

Emily Erickson, center, dances and blows bubbles during a fundraiser party for Disco Chateau, a Burning Man camp organized by technology entrepreneur Ari Kalfayan, at his home in San Francisco, Calif., in June 2015. The camp members were raising money to buy more stuffed animals to bring to Burning Man. Their goal was to create a large "cuddle puddle" where people could cuddle with one another among stuffed animals at the annual festival. Participating in Burning Man and the culture surrounding it has become very popular within the technology start-up community.

Attendees of the Startup and Tech Mixer, a tech industry networking event, mingle with one another on the roof deck of the W Hotel in San Francisco, Calif., in August 2015. The event drew hundreds of attendees. While many companies could be built anywhere thanks to advances in technology, many entrepreneurs feel they need to be in the area to have the networking opportunities required to raise funding and build their companies.

Andrew Hines, center, works on trying fix a problem during a beta launch party for his app Picnic with his co-founder Cassidy Clawson, second from right, at Precita Park in San Francisco, Calif., in March 2015. Picnic is a game that involves taking selfie photos in response to challenges to act out certain emotions. The launch had to be postponed after the co-founders realized the app wasn’t working because Apple’s TestFlight program, which was necessary for the beta testing, was down and not working that day.

Chris Hirst entertains guests in his “Robot Dance Party” costume during a party organized by the co-living house 20 Mission, home to many start-up entrepreneurs, titled “Too Big for Our House” in San Francisco, Calif., in July 2015. The house’s elaborate parties had been getting almost too large for their living space so they decided to rent a venue downtown to host the event. Hirst wears his robot suit, which has speakers built into it, to DJ events and parties around town.

Noor Siddiqui, Conor White-Sullivan, Dylan Enright and Karen X. Cheng, seen left to right, eat dessert during a dinner party hosted by the company WeFunder at their office in San Francisco, Calif., in February 2015. WeFunder is a crowdfunding service that connects start-ups and investors through the internet. The company and it’s founders throw large dinner parties almost every Wednesday for friends and guests from the industry at their office, which also serves as the home of several company employees.

A group of students from Rocket U Bootcamp, a coding school, participate together in a hackathon at Draper University’s Hero City in San Mateo, Calif., in November 2014. There is a shortage of engineers in the area due to the large number of start-ups and coding bootcamps have been popping up to quickly train workers who want to get into the industry.

Lev Konstantinovski takes a nap on a break from the data science program he was attending at the co-working space Galvanize in San Francisco, Calif., in March 2015. Galvanize, a hybrid company that combines tech office space with a school, has several campuses around the country in addition to the one in San Francisco. The campus is themed around San Francisco parks, including this common area, which is built to resemble Dolores Park.

Emily Erickson, center, and her then boyfriend Sean Ahrens, second from left, host guests in their room at 20 Mission, a co-living space, during a party to celebrate the community’s three-year anniversary in San Francisco, Calif., in March 2015. Ahrens and many of the other residents are start-up entrepreneurs and the community is a mix of temporary occupants and people who have made the space their home on a more long-term basis. The residents are allowed to decorate their room however they like and some of the long-term residents, such as Ahrens, put much effort into designing creative spaces.

Connor McGill, second from right, smokes cigars with his co-workers on his last day of work at Hackers/Founders, an organization that helps early-stage entrepreneurs located in the Hacker Dojo in Mountain View, Calif., in August 2014. McGill was leaving his job to pursue an undergraduate degree at UC Davis.

Raphael Dardek, left, a co-founder of Weeleo, relaxes in the bed where he was temporarily staying at a fraternity house in Berkeley, Calif., in August 2014. Dardek and another co-founder spent the summer couch surfing in order to save money while in San Francisco from France to participate in an accelerator program.

A participant in a hackathon organized by the company Shirts.io sleeps at her computer during the in San Francsico, Calif., in August 2014. This hackathon lasted 37 hours and many participants stayed the entire time, taking breaks to sleep where and when they could.

An attendee of the Startup and Tech Mixer tries on a virtual reality product that was on display at the tech networking event at the W Hotel in San Francisco, Calif., in August 2014. The event is held once every few months and draws hundreds of attendees looking to make connections in the industry. Virtual reality is looked at as one of the most promising upcoming trends in the technology industry.