Job title: Senior manager, web development at LinkedIn
Why she's powerful: LinkedIn would be nothing without its website and Sarah Clatterbuck sets the technical standards for web development and leads several web development teams.
She's a big believer in Web Accessibility, too, making the web easier to use for people with disabilities and leads the company's task force on that. Clatterbuck is also a mentor for girls learning to code in the Bay Area.
No. 21: Box, Divya Jain
Job title:Staff data scientist and engineer lead at Box
Why she's powerful:Jain joined Box in 2013 when Box bought the technology behind dLoop, the company she cofounded. (Box is careful not to say that it acquired the whole company.) dLoop is a data analysis tool that helps enterprises discover information and insights.
Now she's leading a project that will help Box's customers search and analyze documents.
Jain previously held roles at EMC, Kazeon Systems (acquired by EMC), and was senior software engineer at Sun Microsystems. She holds a graduate degree in data mining and analysis from Stanford.
No. 20: Citrix, Ashi Sareen
Job title:Director of product development for the mobility team at Citrix
Why she's powerful:Citrix is a $3 billion company with 7,000 employees. Its flagship product helps enterprises run apps over the network on any device.
Ashi leads product development for the company's important mobility product called XenMobile. She runs a team of about 33 people, six managers, each of whom manages their own teams.
No. 19: Box, Tamar Bercovici
Job title:Senior manager of Backend Engineering at Box
Why she's powerful:Bercovici joined Box in February 2011 as the first woman hired to its infrastructure department, known as the "Backend Engineering" team.
She's now a senior engineering manager where she leads a database project, known as Distributed Data Systems Team.
Bercovici is also in charge of Box’s twice-yearly Hackathon and is active on the speaking circuit. She's given talks at the Grace Hopper Celebration of Women in Computing, Percona Live and Velocity Europe.
Prior to Box, Bercovici was an early-stage employee at XMPie (now a Xerox company).
She holds a doctorate in computer science from the Technion Institute of Technology, the Israeli version of MIT.
Job title:Manager, production engineering at Facebook
Why she's powerful: Blount leads teams managing some of the most complex systems at Facebook. Those teams build and run systems that support Facebook's other engineering teams.
She landed at Facebook after it acquired email productivity app MailRank, a company she cofounded in 2010. She also worked as an engineering director at Linden Lab (makers of Second Life) and as vice president of software engineering for British music producer EMI Group.
No. 17: Box, Heidi Williams
Job title:Director of platform engineering at Box
Why she's powerful:Williams has been leading the platform engineering unit since she joined the company just over a year ago. Her team is responsible for supporting third-party developers including creating various "application programming interfaces" that let developers write apps for Box.
She's also an executive sponsor for Box's Women in Tech community of women engineers where she helped create a corporate mentoring program.
Previously, Heidi spent 17 years at Adobe joining the company through its acquisition of Macromedia.
No. 16: Oracle, Elena Zannoni
Job title:Director of Linux engineering at Oracle
Why she's powerful:Oracle is a big player in the Linux world, supplying its customers with a version of the Linux operating system based on Red Hat's Linux.
She came to Linux from years working on other open-source projects, starting at Cygnus Solutions bought by Red Hat and then hired away by Oracle. She's a regular Linux conference speaker and she volunteers to organize the Linux Plumbers Conference.
Job title:Director of growth engineering at LinkedIn
Why she's powerful:Lockheimer has built LinkedIn's growth engineering team into a powerful force within the company. She leads this team as a separate group within the engineering organization. Its mission is to build tech that encourages more people to join LinkedIn.
She's also a board member for the Anita Borg Institute.
Prior to LinkedIn, Lockheimer was a director of engineering at Good Technology.
No. 14: Facebook, Rachel Peterson
Job title:Director of data center strategy and development at Facebook
Why she's powerful:Facebook prides itself on building state-of-the art green data centers. Peterson is responsible for Facebook’s global data center location and energy strategy, over 2 million square feet of data center space that support Facebook's 1.2 billion monthly active users.
She'll even negotiate deals to supply those data centers with green energy. For instance, Facebook's Lulea, Sweden, and Altoona, Iowa, data centers are powered by 100% renewable energy.
Rachel has been at Facebook for over four years and has helped create the company's Women in Infrastructure and IT program at Facebook.
Why she's powerful:Kabam makes some extremely popular free video games like "Kabam's Kingdoms of Camelot" franchise which has grossed more than $250 million in four years, the company says.
Kabam recently extended its partnership with Warner Bros. Interactive Entertainment to make games based on "The Lord of the Rings" movies and the upcoming "Mad Max" film, too.
As cofounder Liu leads the HR team for more than 800 employees worldwide. Before focusing on hiring, she led the product design for the "Kingdom’s of Camelot" games.
Prior to Kabam, Liu was senior user interface designer for AOL, where she led the design of community web products.
No. 12: Yahoo, Yoelle Maarek
Job title:Vice president of research at Yahoo
Why she's powerful:Maarek leads research for Yahoo and heads research teams in Israel and India.
She works on research projects with academia (and has published a boatload of academic papers on the topic) while also working with engineering and product teams to tackle scientific challenges that change Yahoo's business.
Prior to Yahoo, Maarek founded the Google Haifa Engineering Center and was a Distinguished Engineer at IBM Research.
Why she's powerful:Shah heads up heads up Chrome development at Google. She was one of two women to give presentations at Google's recent developer's conference I/O. This was notable because Google is really trying to up the profile of women in tech and it needed it to begin by showing some of its own women engineers in leadership positions.
She showcased Chrome working with Google's newest version of Android, L.
Shah, an MIT graduate, has been at Google since 2003 and previously worked on the Google Toolbar and Google Notebook, according to her LinkedIn profile.
No. 10: Google Nest, Yoky Matsuoka
Job title:Vice president of technology at Nest
Why she's powerful:Matsuoka is in charge of the user interface and self-learning aspects of Nest's thermostat. Nest is one of the Valley's most watched tech companies, cofounded by ex-Apple exec Tony Fadell and bought by Google for $3.2 billion. Nest is now buying hot startups of its own. It just acquired Dropcam for $555 million.
Beyond Nest, Matsuoka is known for her work on robotics and neuroscience, working on more realistic prosthetics. Prior to Nest, she was the Head of Innovation at Google and a professor of computer science and engineering at the University of Washington.
In 2007, she received the MacArthur Genius Award. It came with a $500,000 no-strings-attached prize.
She graduated from UC Berkeley and earned an master's and doctorate in electrical engineering and computer science from MIT.
No. 9: Pinterest, Nadine Harik
Job title:Engineering manager, web at Pinterest
Why she's powerful:Harik oversees the company's web and mobile web teams.
She's been at Pinterest since 2012. Before that she worked as a senior software engineer at Google working on some of its most important products including AdWords, ads for YouTube and Google Apps.
She says people constantly assume that a woman working in tech has a non-technical job like human resources or community management. So when she talks about career, "now, I tend to always preface with, 'I work at Pinterest and I'm an engineer at Pinterest,'" Hariktold Business Insider.
Job title:Vice president of the software and services group at Intel
Why she's powerful:Whalen is an Intel vice president and a software engineering director in the Open Source Technology Center (OTC), a team she helped found. She and her team are responsible for a lot of open-source projects including the company's contribution to Linux.
Whalen has been with Intel for 18 years, beginning her career as a quality assurance software engineer. The company has twice honored her with its Intel Achievement Award, most recently in 2014 for leadership of a product called the Intel Hardware Accelerated Execution Manager (HAXM), which makes Android apps run faster on Intel devices.
No. 7: Facebook, Delfina Eberly
Job title:Vice president of infrastructure data center operations, Facebook
Why she's powerful:Eberly runs the data center operations team which is responsible for worldwide installation and maintenance of Facebook's networks.
These are the teams that beef up Facebook's computer systems to make sure they can handle over a billion users photos, videos, chats, and status updates.
Prior to Facebook, she was CIO at email service provider Critical Path (acquired in 2013 by Openwave Messaging) and she ran consulting teams for Exodus Communications.
No. 6: Yahoo, Merline Saintil
Job title:Head of global engineering operations at Yahoo
Why she's powerful:Yahoo is making a massive shift toward mobile and Saintil runs the global engineering for Yahoo's Mobile & Emerging Products team.
Prior to Yahoo, Saintil was writing software and managing systems at Sun Microsystems, Adobe, PayPal, and Joeyent Inc.
She also works with Watermark, a nonprofit for executive women and is on the Alumni Board of Directors for Carnegie Mellon University.
No. 5: WiTricity, Katie Hall
Job title:CTO at WiTricity.
Why she's powerful:Imagine holding a lightbulb up in your hand as it turns on, using electricity from the air, no wires attached.
That's the kind of thing Hall is working on. She's helping to create safe wireless electricity through a startup called WiTricity.
The tech doesn't put electricity into the air, so there's no chance of getting zapped like a lightening bolt. It uses magnetic fields used to transfer energy, she told Wired.
Right now it's mostly being used to wirelessly charge devices. WiTricity and Intel just struck of a partnership deal to embed the wireless charging tech into Intel-powered devices.
Hall joined WiTricity in 2007 as CTO. Prior to that, she cofounded several companies that created communications equipment (Wide Net Technologies and PhotonEx). She also worked at MIT’s Lincoln Laboratory and AT&T Bell Laboratories.
She holds eleven U.S. patents and a doctorate in electrical engineering and computer science from MIT.
No. 4: IBM, Tal Rabin
Job title:Manager and a research staff member of the cryptography research group at IBM’s T.J. Watson Research Center.
Why she's powerful:Rabin's early career was almost like the movie "Good Will Hunting." When she was a student, she solved a math problem that experts thought couldn't be solved. (It's complicated, something to do with calculating numbers when most of them are not known, she told Business Insider).
She's also chairs conferences and professional organizations in her field. She has a doctorate in computer science from the Hebrew University of Jerusalem and was a postdoctoral Fellow at the MIT Laboratory for Computer Science.
Why she's powerful:Ullal is CEO of Arista Networks, which competes with Cisco by offering superfast network equipment for data centers.
Ullal just led Arista to a fabulous IPO in which the stock was priced above the high end of its initial range at $43. It popped big the first day (up 40%) and is still trading at around $70. She offered investors something they hadn't seen in a tech IPO for a while: profits.
Ullal, a well-respected engineer in the network industry, weathered it all with aplomb. She came to Arista from Cisco, where she had been a senior vice president for its uber important, $10 billion data center, switching and services group.
No. 2: Intel, Carolyn Duran
Job title:Conflict minerals program manager and supply chain director at Intel
Why she's powerful:Imagine personally ending slavery in some of the poorest, most violent places in the world. That's what Duran is doing with her job at Intel.
Most of us have heard of "blood diamonds" that come from war-torn areas in Africa. Many consumer electronics use materials from mines run by brutal warlords, too. They are known as "conflict minerals."
Duran led Intel's efforts to stop using these minerals. Instead of simply buying from other mines, her program worked with mines in the Congo to get them to stop using slave labor. After years of this work, the company is producing chips made with 100% conflict-free minerals.
To date, her team has met with more than 85 smelters in 21 countries to develop better employee practices. This work led to a global Conflict-Free Sourcing Initiative.
Inside Intel, she also leads a team of technologists who makes sure that the minerals meet other worldwide chemical laws.
She's been with Intel since 1998, starting as a process engineer in research and development. She earned a doctorate in materials science and engineer from Northwestern University.
No. 1: SpaceX, Gwynne Shotwell
Job title:President of Space Explorations Technology Corporation (SpaceX)
Why she's powerful:Shotwell is responsible for day-to-day operations for arguably one of the most exciting companies on the planet, and off it.
SpaceX designs, manufacturers and launches rockets and has a $1.6 billion contract with NASA to carry supplies to the International Space Station. But the company's ultimate goal is "enabling people to live on other planets," it says.
She joined SpaceX in 2002, the year it was funded, as vice president of business development and helped build the Falcon family of rockets, leading them to over 40 launches, and $3 billion in revenue.
She is also on SpaceX's board of directors.
Prior to SpaceX, Shotwell spent more than a decade at Aerospace Corp. holding engineering and tech positions, working herself up to chief engineer of a satellite program. She also managed a landmark study for the FAA on commercial space transportation, too, and was a director of Microcosm's Space Systems Division.
She's involved in science and tech education through the Frank J. Redd Student Scholarship Competition, helping it $350,000 in scholarships in six years.
Shotwell has master's degrees from Northwestern University in mechanical engineering and applied mathematics and has penned dozens of papers on spacecraft design and engineering.