Board of Directors

Martin Handwerker, President

After studying at Cornell University and receiving Bachelors and Masters degrees in Computer Science, Martin married and moved to Silicon Valley where he has lived for 17 years. He worked at software companies specializing in speech synthesis, customer relationship management, and streaming databases. He lead a team at Microsoft responsible for designing the backing storage system for OneDrive, managed a team of developers responsible for the user visible parts of, and most recently is leading a team at Google responsible for selecting which ads are displayed on mobile devices. He is a father of SPHDS students in the fifth, seventh, and eighth grades.


Linor Eylon, Vice President

Linor is passionate about Jewish day school education and has devoted 20 years to working with Jewish children. From synagogue youth director in Encinitas, California, to preschool teacher and director in Tacoma, Washington, to preschool founder in Olympia, Washington, and finally to Sunnyvale where, for 10 years, Linor taught and directed in South Peninsula Hebrew Day School’s Gan Aviv. Linor graduated, Summa Cum Laude, from San Diego State University with a B.S. in Child and Family Development. For her teaching at SPHDS, Linor was the recipient of the prestigious Grinspoon-Steinhardt Award which honors outstanding Jewish educators throughout North America. Linor along with her husband, Eyran, and their 3 children have lived in Sunnyvale for the past 14 years. Linor and Eyran are proud former SPHDS parents where all 3 children are alumni of the school and have since moved on to Kehillah Jewish High School, the Israel Defense Forces and college.


Ari Tuchman, Treasurer

Ari is co-founder and CEO of Quantifind. a predictive analytics company. He received his doctorate in atomic physics from Yale University focusing on Bose Einstein condensation. Ari is the father of Danelle and Natalia and is married to Liora Schultz. He also gives a women’s advanced talmud shiur in the community.


Nissa Johanix, Past President

Nissa Johanix is the mother of Elazar (entering Second grade) and Amichai (Kindergarten) at SPHDS. She served on the SPHDS Board from 2009-2012. She is an alumni of SPHDS, having attended grades K-8. During college, she ran the SPHDS B’nei Akiva after-school program and worked in the SPHDS office. Currently Nissa is serving as a member of the Search Committee for the Executive Director, Principal and Early Childhood Education Director. Outside SPHDS, Nissa is active with several Bay Area Jewish organizations including AIPAC, Jewish Federation of Silicon Valley, Jewish Community Federation of San Francisco, Congregation Kol Emeth, and The Friendship Circle. With her many years of active participation in the affiliated Jewish community of Silicon Valley, Nissa has developed relationships with key leaders from a wide variety of Jewish institutions and has experience navigating the nuances of our community. In addition to her volunteer roles, Nissa is trained as a birth and postpartum doula, and is passionate about yoga and cooking. Nissa’s husband, Tom, works for a tech start-up, and volunteers with several Jewish organizations.


Maury Alcheck, Director

Barry Berkowitz, Director

Eran Leib, Director

Adinah Katz, Director

Ian Prager, Director

Bonnie Rosenberg, Director


Esther Rosenfeld, Director

Esther is a strong proponent of the importance of Jewish day schools in promoting and preserving Jewish identity. She grew up in New York, where she attended Solomon Schechter day school and Hebrew Academy of Nassau County, and her daughters have attended/are attending SPHDS, Yavneh and Kehillah Jewish high school locally. Esther is an attorney who has been practicing family law in San Mateo and Santa Clara counties for about 15 years, earning accolades for excellence in practice. Esther and her husband Shachar, an accountant, are almost a Jewish joke: they missed the "doctor" part.


Dr. Liza Shiff, Director

Liza is the mother of two current SPHDS students. As a Los Altos native, she and her family have strong ties to the community; her parents served on the SPHDS board many years ago and she and her brothers are graduates of SPHDS. She has been very involved in school volunteer work, currently serving on the walkathon committee and as a grade 2 room parent. She is a physician and has contributed to the medical profession in numerous capacities, including previous service as local president of the American Medical Women’s Association and serving on the executive council of the Santa Clara County Medical Association.


Nathan Thomas, Director


Ilana Westerman, Director

Ilana Westerman is the co-founder and CEO of Create With Context. She believes that technology can make the world a better place by helping people to learn, grow, communicate, gather, create, work, buy, and have fun. Under Westerman’s leadership, the company has become a thought leader in digital trends, sought out by news sources including The New York Times, NPR, SWSX, Forbes, the FTC, etc. to provide insights on emerging digital technology and its impact on people.
Prior to co-founding Create with Context in 2005, Westerman worked on IBM’s web presence for the Nagano Olympics and was one of the early members of Yahoo!, where she helped build the Yahoo! UX team. She has also shared her passion for context-driven design as an adjunct professor at San José State University.
Ilana’s older son Sam attended SPHDS for pre-school and her younger son Max graduated from the 8th grade in 2016.