For Marissa Mayer ’97, M.S. ‘99, one of the most important things about a job is working with intelligent people.

“When you work with the smartest people you can find,” she said, “it really challenges you to push yourself.”

And there was no shortage of bright minds at the School of Engineering’s 11th annual eDay, which brought over 500 alumni and family members back to campus on July 17 to take classes on this year’s theme of “Techxtravaganza.”

A number of Stanford professors and Mayer, the keynote speaker and vice president of Search Products and User Experience at Google, taught the “Techxtravaganza” classes, which drew upon this year’s focus on electrical engineering and computer science.

Tickets for eDay sold out two days before the event started, which Nancy Peterson, the school’s director of communications and alumni relations, attributed to the amount of interest from former Stanford students.

“People want to be lifelong learners,” she said. “They want to be familiar with what’s going on with research, and they’re interested in knowing who the faculty [members] are.”

Some of those faculty members offered groundbreaking ideas with the potential for worldwide impact. Balaji Prabhakar, professor of electrical engineering and computer science, explained the success that a lottery-like system could have with waste reduction in a “Societal Network” such as transportation or healthcare. Dan Boneh, also a professor of electrical engineering and computer science, presented ways in which the technology involved in social networking security could be improved to reveal less information to third parties.

Other classes, geared primarily toward the nearly 250 children at the event, gave a basic introduction to engineering and programming. Computer science professor Mehran Sahami taught simple programming skills using a robot named Karel, while electrical engineering professor Brad Osgood used clips from “Lord of the Rings,” as well as the sound produced by his trombone, to help children understand the ways in which communication could work.

In her keynote address, Mayer encouraged the youth in attendance to pursue a career in engineering.

“The amazing thing for me about computer science,” she told the audience, “was that there was a new problem every day.”

Although children might not be able to experience that sense of excitement and discovery every day, their parents hope that they will in the future. Peterson said that a large part of the event’s appeal each year is its inclusion of children.

“Those who have children are interested in exposing them to the excitement of engineering, and that reinforces the parents’ interest in encouraging the kids to study science and math,” she said.

Stanford students presented the products of such studies in the form of demos during the event’s lunch break. One stand allowed participants to control robots using an Android phone, while another featured a haptic device, which works like a 3D mouse for entertainment and medical purposes.

Each year, the School of Engineering tries to find a theme that will involve more than one of its nine departments, so as to include as many professors as possible in eDay. Last year’s event, themed “Planet Green,” combined the disciplines of materials science, chemical engineering, civil engineering and environmental engineering. Although the idea of sustainability was the primary focus last year, it still had an influence on eDay 2010, as even the silverware, cups and plates were replaced by compostable equivalents.

The caliber of the presenting professors, many of them industry leaders, also draws alumni back to the event. Although professors may not initially know about eDay, they enjoy the event once they have been asked to speak, according to Peterson.

“If they’ve not participated, it’s hard for them to know what the experience is to be on campus on a Saturday with 500 people,” she said. “And they tend to find it really enjoyable.”