Lesly attended the University of California, Davis where she earned a BS in Biological Sciences. She is pursuing her Masters of Science in Nursing with a family nurse practitioner specialization. Lesly has spent the last five years working in both the medical and educational fields. She previously worked as a 7th grade math teacher at Prospect Sierra Middle School. In her spare time, she enjoys exploring, spending time with her family, and serving at her local church.Lesly Ayala, B.S.
Marta Blanchard, B.A.
Marta has a B.A. in English from Lewis and Clark College in Oregon, with a minor in Classical Studies. She continued studying Classical Studies at the graduate level, but realized that her passion was in education, and spent several years tutoring and teaching English, history, and math to middle and high school students before joining the Tilden family in 2017. She has a teaching credential in English, and believes that all students are capable of becoming strong readers and writers with the right support and guidance in finding the stories they love. She also enjoys delving into the depths of history to find the reasons behind any given event, and does her best to share the most interesting historical details with her students (and anyone else who will listen). She teaches English, history, social sciences, and Latin. In her spare time, she likes reading, drawing, and tabletop gaming.
Pamela Brenman, M.A.
Pamela is a native New Yorker, but has spent most of her adult life in the Bay Area. She earned a B.A. in English Literature/Writing from Rider University, and an M.A. in English Literature from Rutgers University. After moving to the Bay Area, Pamela began her career as an educator teaching English and Humanities at private middle schools and has served as an Assistant Head of School as well. Pamela joined Tilden’s faculty in 2021. A life-long learner, Pamela attended Mills College and earned a Masters in Educational Leadership. She is in the process of completing her dissertation in the Ed.D. program at Mills College- Northeastern University. Her philosophy of education values the mind,the heart and progressive pedagogies. She believes that her mission as an educator makes it possible for students to become themselves and find their individual voice. Pamela is a Bay Area Writing Project Consultant and a member of the Facing History and Ourselves ELA Advisory Board. On weekends, Pamela loves to walk the many beautiful trails in the Bay Area.
Miguel Chan, B.S.
Miguel previously worked as a Math Empowerment Teacher for the nonprofit organization Making Waves Education Program located in Richmond, CA. Here he supported low income students in a one-to-one setting. Miguel found Tilden’s Prep model to be nearly identical to that of his previous job. Intrigued with this similarity, he started teaching at Tilden Prep in June, 2013. Miguel holds a B.S. in Mechanical Engineering from UC Berkeley and teaches a variety of courses including math through Calculus BC, chemistry, physics, and computer science. In his spare time he works as an online math curriculum developer and webmaster for "MathFortress.com", an educational website that he created for the purpose of expanding his reach to a greater audience via unique video tutorials for various mathematical disciplines.
Coral del Mar Ramos, B.A.
Coral del Mar is a native of Puerto Rico. With the island being a gateway to the Caribbean and popular tourist destination, at a young age Coral recognized that language and cultural knowledge were keys to unlocking insights into other worlds, which inspired her journey with American Sign Language and Deaf Culture. Coral graduated from the University of Puerto Rico, Carolina with a Bachelor's degree in Cultural Tourism, extensively studying ASL. In her students, she seeks to ignite the passion she has found for ASL and other languages and cultures around the world and around us every day.
Keiko was born and raised in Tokyo. She started tutoring middle and high school students while in college, and following graduation, taught English and later became certified as a Japanese language teacher in Japan. She started teaching Japanese at Tilden in 2007, and has enjoyed teaching from Japanese 1 through the AP level to many students. She also enjoys watching Japanese anime, drama, and movies. In her spare time, Keiko enjoys flower arranging, and is a licensed teacher of Ikebana (Japanese flower arrangement).
Bjorn Fox, M.A.
Bjorn Fox has an undergraduate degree in Mechanical Engineering from San Francisco State University and a Master's Degree in Management from Cal State East Bay. Bjorn has one year of experience working as a substitute teacher in small to medium sized classrooms and experience as a tutor. He joined the Tilden team as a math and science teacher in 2022.
Gabriel Fredericks, B.S.
Gabriel is a recent graduate of UC Davis with a B.S. in Mathematics. Before completing his degree, he tutored privately in Solano and Marin counties for four years and at Solano Community College for another three. Gabriel greatly enjoys getting to know his students. He believes that every student has their own unique way of learning, understanding concepts, and solving problems and he works to develop the individual skills of his students while learning from the strengths of each one. For hobbies, Gabriel enjoys fitness, chess, discovering independent music artists, and solving puzzles and math problems. On weekends, he plays Dungeons and Dragons with friends.
Joshua Harris, M.A., M.F.A., J.D., History Department Head
Joshua Harris grew up in Wyoming and received his B.A. from Brown University. After graduation, he worked at a Native American boarding school in South Dakota and served in the US Peace Corps in Mali, West Africa. Josh then earned his J.D. from UC Davis and practiced environmental law for ten years before attending and teaching creative writing and fiction classes at SFSU, where he earned an M.A. in English and an M.F.A. in Creative Writing. In 2019, he published his first novel, Unorthodoxy.
Rachel Hertog, Ph.D., Science Department Head
Rachel graduated from San Francisco State University with degrees in Marine Biology (BS) and Ecology and Systematic Biology (MS). From there, she continued her research at UC Davis in the Geology department with a concentration in Paleobiology. Before coming to Tilden in 2017, Rachel worked in the public programs department at the Exploratorium and deep in the shelves of the Invertebrate Zoology and Geology collections at the California Academy of Sciences in San Francisco. She has a life-long dedication to inquiry-based science and exploration of the natural world. When she's not at Tilden, Rachel enjoys open-water swimming in the Bay, sailing, drawing, and experimenting with fermented foods.
Zoran Kurtovic, Ph.D.
Born in Los Angeles and raised in Brooklyn, Zoran earned a Bachelor of Science in Chemistry at Lafayette College and a Doctor of Philosophy in Chemistry at the University of California, Berkeley. In addition to teaching Chemistry at UC Berkeley Extension and privately tutoring high school and college students taking chemistry, physics, and math classes, he has held a variety of software positions, including in developer and tester roles. His first love is chess, and Zoran is proud to have played third board on the Stuyvesant High School national champion chess team his senior year. Interest in puzzles, other games, math, sciences, and software followed. He enjoys the "Aha!" moment when teaching as well as when learning.
Charles McLeod, M.F.A.
An East Bay native, Charles has a B.A. in English Literature from the University of Iowa and an MFA in Creative Writing from the University of Virginia, where he was a Hoyns Fellow. He's received additional fellowship from the Fine Arts Work Center in Provincetown, and San Jose State University, where he was a Steinbeck. The author of a novel and two story collections, he's won a Pushcart Prize and The Iowa Review's Fiction Award, and his stories and essays have appeared in more than two-dozen publications.
Christian Merino, M.A.
Christian Merino was born in the Bay area and identifies as both first generation and Mexican American. Outside of school, Christian enjoys Latin dancing, running, playing soccer, and hanging out with friends. As an undergraduate, Christian attended U.C. Berkeley and got a Bachelor’s Degree in Physics in 2016. After graduating, Christian started working at his former high school, Berkeley High, in order to give back for all the school had given him. In 2018 Christian went to Michigan to attend graduate school and pursue both a Masters in Physics and Doctorate in Science Education - Physics. Christian received his Masters in 2020 and attended graduate school with the hope of increasing diversity of students traditionally underrepresented within physics. Christian was a teacher at Tilden in both 2017 and 2018 and I am extremely excited to be back.
Sonia Mahini, M.P.H.
Xuannga “Sonia” Mahini is a graduate of the University of California, Berkeley, with a BA degree in Biochemistry and a Master of Public Health (MPH) degree. Prior to joining Tilden Prep in 2021, she worked for various national and international environmental consulting firms and the Electric Power Research Institute. In her role as Regional Director, Manager, or Principal, she has trained numerous chemists, engineers, environmental professionals, and toxicologists to perform comprehensive risk assessments for the protection of public health and the environment. She enjoys tutoring her son and his friends in all subjects, as their needs arise. She is currently living in Berkeley with her family and enjoys cooking, gardening, home construction, designing jewelry, sewing, and taking care of her aging neighbors.
Ford Messi, B.A.
Ford has two Bachelor Degrees: one in Economics from the University of International Business and Economics, and a second in Applied Accounting from Oxford Brookes University. He also holds two professional qualifications-ACCA\CGMA and has over 27 years of teaching experience.
Aicha Nystrom, B.A.
Aicha is a mom to two beautiful, creative young adults. She worked on art projects with preschoolers to high school seniors, actively helped organize, photograph performances, field trips, camps, concerts, art projects, fundraisers, cook outs, drama productions. Aicha was a volunteer trip leader for people with disabilities and under-resourced youth with ETC's winter ski program. She speaks several languages and has lived on four continents; Aicha enjoys most people and appreciates quirkiness and originality in others. She is passionate about photography, and specializes in triptychs. Her work is collected by art collectors, clients and friends all over the planet. Aicha has B.A. in architecture with a minor in photography and sculpture from Pratt Institute, studied photography at Camera Obscura, political science at the University of Tel Aviv, and enjoyed woodworking classes at Laney College. She loves to live, cook, eat, hike, kayak, travel, learn new things, build and be with her family and friends. Aicha joined Tilden teaching art and photography in 2022.
Betsy Romans, B.A., B.S.
I am originally from West St. Paul, Minnesota. I spent 4 years in Vermont where I studied Biology (BS) and Education (BA) at Middlebury College, and taught middle and high school Science. At Tilden, I teach STEM and am committed to inquiry and experiential-driven learning. Outside of school, I was a musher for a local dog sledding yard. My current hobbies include snowboarding, rugby, knitting, and hiking.
Corey Skinner, B.A.
Corey is a San Diego native with a degree in mathematics/computer science from UCSD. He has a seven-year track record as a private tutor helping students achieve their academic goals and working professionals transition to a career in programming. Recognizing the challenges in STEM, he is motivated to be a supportive teacher, simplifying complex concepts, with the goal of empowering students in the pursuit of their greatest academic dreams. His philosophy as a teacher is to make learning enjoyable by helping students see the real world applications of math and gain a deeper appreciation for numbers. Outside of teaching, Corey’s favorite hobbies are going to the beach, playing guitar, and hiking.
Mason Slack, B.A.
Mason has a B.A degree in Political Science and Government, with a minor in History from Miami University in Ohio. His outstanding commitment is to educate people on the importance of History and Civics. He believes in the famed quote by Mark Twain, "History doesn't repeat itself but it often rhymes."
Ana Tafur, M.A.
Ana Tafur is a Spanish and Latin American literature teacher She graduated from University of California, Davis. She has taught Spanish and Latin American literature to students of all ages for the past fifteen years. In her spare time Ana enjoys cooking, reading poetry books, watching documentaries, learning Portuguese and walking in nature with her husband and her mini Shnauzer Pandita.
Dylan Thiermann, B.S.
Dylan received his B.S in Mathematics from the University of Chicago. He previously taught at Head-Royce School in Oakland, and is invested in and inspired by seeing students go from bewildered to enlightened. In his free time, he plays ultimate frisbee and pickleball.
Walnut Creek Campus
Fassil Bekele, M.S.
Originally from Ethiopia, Fassil came to the U.S. after finishing high school and is now a naturalized U.S. citizen. He holds a Bachelor's degree in Mathematics from the University of Chicago, with a minor in Statistics. He has also done graduate studies in mathematics at Cornell University and holds a Master's degree in Computer Science from Cornell. Fassil has worked extensively in the financial services industry in New York in various capacities as an analyst, software developer, and manager. He loves mathematics, enjoys teaching, and has taught for over ten years. Fassil has a talent for strategy board games such as checkers, chess, shogi and go and is rated amateur 3-dan in shogi. Among the things he currently likes to do in his spare time is watching chess engine competitions. He enjoys Japanese enka songs, traditional Korean music, opera, and a variety of other music.
Reed Burkhart, M.S.
Reed holds degrees in Mathematics, Computers and Electrical Engineering from the California Institute of Technology and UC Santa Barbara. He has used his science skills as a space engineer, designing satellites, as well as balancing these left brain activities with surfing, music, dance and other more right-brained, artistic and athletic explorations. At Tilden, Reed helps students to break down abstract math or science concepts into their simplest essence, so helping students to achieve mastery whether math and science come easy to the student or not. Reed believes that there are as many different ways to learn as there are people, and that the key to learning is really as simple as a motivated student and an inspiring, caring teacher.
Tim Burkhart, B.S., B.A.
Tim obtained a Bachelor of Science degree in Physics and a Bachelor of Arts in Computer Science at UC Santa Cruz. He joined Tilden teaching math and science in 2022 after previous experience as a substitute teacher and a tutor. Tim likes teaching one on one to greatly assist students in how to think, learn and program.
Will Beazley, B.A.
Will has loved mathematics as far back as he can remember. When he discovered some of the connections between mathematics and music, Will began to dedicate his own time into investigating these interrelationships further. Eventually, he earned his BA in The Mathematics of Music from George Mason University. While tutoring there, he learned that, not only was he good at understanding mathematics, but also able to help others do the same. Soon thereafter, Will earned his Master’s in Education from the University of Phoenix in San Jose. Since then, Will has been teaching, tutoring, and creating curricula for mathematics and electronic music courses for approximately twenty years. When Will is not teaching mathematics or music, he is often exploring them himself. One of Will’s favorite hobbies is cooking vegan food.
Cliff Escobedo M.A., Foreign Language Department Head
Cliff was born and raised in Mexico City until the age of 11. His family decided to move to the United States to seek better education opportunities for his brother and him. While attending College Park High School in Pleasant Hill; Cliff discovered that he had a passion for teaching and helping others with class work. Throughout his high school years, Cliff, his best friend Matt, and his brother held tutoring sessions during lunch in math, French and Spanish. During High School is when he knew he wanted to be a professor/teacher. After high school, Cliff went off to college and received a degree from U.C. Berkeley in Spanish Literature and Language. A couple of years later, he completed a Master's program at San Francisco State. Cliff has tutored middle school and high school students for over 15 years and has taught college level courses for 5 years at D.V.C, St. Mary’s College, and Holy Names in Oakland. When Cliff is not working at Tilden or at one of the colleges, he loves going to the movies and traveling. He spends too much time at the movies! Another fun fact: he and his brother are twins.
Farhad Fazel, M.S.
Farhad has a Bachelor of Arts in Biology, and is currently pursuing a Master’s of Science in Physics at San Francisco State University. He has a notable interest in medical physics, and has published work in diagnostic radiology. He also has research experience in chemical ecology, soil science, and plant pathology, at UC Davis and UCSF Medical Center. Farhad became part of the Tilden faculty in 2022 teaching math and science. He is also a bibliophile, particularly in the realm of philosophy and anthropology. Farhad also spends a lot of time playing beach volleyball on a competitive basis, and coaching for various skill levels.
Sam Froehlich, B.A.Sam Froehlich has a Bachelor's degree in English from CSU East Bay. She has always had a passion for literature and English, and loves to help others learn to love reading as much as she does. To learn to read and continue learning in your life beyond school is one of the most important takeaways that makes life more enriching and successful.In her free time, Sam enjoys reading, sewing, painting, baking, gardening, and walking her dog. She also loves comic books, science fiction, and superhero movies!
Matthew Goldie, B.A.
A proud Canadian citizen, Matthew studied Cognitive Science at McGill University in Montreal. In addition to teaching at Tilden, he works as a private tutor, and enjoys thinking of new ways to explain content. He favors a one-to-one approach because it allows him to adapt to the needs and interests of individual students. In his spare time, he enjoys cooking and reading lots of books. His interests include color terminology, Netherlandish paintings, and philosophy of language.
Claire Girodie, M.F.A.
Claire is a French native who studied business, followed by math and physics, in France. She holds a M.F.A. in Studio Arts from Towson University, MD, and her work has been extensively exhibited on the East Coast, in Illinois, Texas, New Mexico, and Scotland.
From figurative paintings to abstract drawings or installations, her work explores the unspoken, the ignored, and the power of silence. Claire carefully chooses her mediums for their emotional, historical and cultural values, or the implied meanings of their physical properties. Prior to moving to California, Claire was a lecturer in French and an Adjunct Professor in Visual Arts at Towson University in Maryland and the University of Baltimore. She teaches French at Tilden Prep, and loves sharing anecdotes about the French language with her students. Claire enjoys learning about anything and everything, and in her free time, you will find her outside reading, gardening, hiking, or working on some project.
Lauren Gatzka, B.A.Lauren is a Bay Area native and has been teaching English for over ten years. She graduated
cum laude from Southern New Hampshire University with a Bachelor of Arts degree in English
Literature. Before coming to Tilden, she began working toward her Master's in English Literature which she will be completing in the Spring of 2025. On Lauren's journey toward earning her degree, she trained to be an opera singer and subsequently built a business teaching private voice and piano lessons. Though music is a passion of Lauren’s, reading was her first love. To
this day, Lauren is just as passionate about reading as she was in first grade and is excited to
help her students realize their passion and talent for reading and writing at Tilden. When Lauren is not teaching, she loves to spend time with her family and her dog, garden, and
attend live performances
Liam Kresbach, B.S.
Born and raised in Austria, Liam has roots in the Bay Area and received his B.S. in Biology from Gonzaga University. During his time as an undergraduate, Liam tutored students ranging from elementary school through adults in the Life Sciences, Mathematics, and Foreign Languages. After graduating, he spent three years working in special education, literacy and reading comprehension remediation. In his spare time, Liam enjoys the outdoors, travel, and cooking.
Cerys Morgan, B.S.
Cerys Morgan holds a degree in Statistics with a minor in Ethnic Studies from University of California Berkeley. After working as a research assistant at the Data Science Institute in London, England, she realized she wanted to put her knowledge to good use and became a tutor in both math and English. She believes that the connection a teacher has with a student can create a passion or interest in that subject and that teachers have a real place to make a change in the world. Being capable of teaching both math and English, she was able to help create a curriculum for a reading program upon her return from the UK. She strives to bring some light, organization and positivity to the Tilden Team. Outside of school, she loves to spend time with family, travel back to the UK to see her mother, grandmother and friends, as well as loves to spend time finding new and interesting shows on Netflix
Susana Maltez, B.S., Science Department Head
Susana earned her degree in Earth Science from UC Santa Cruz. She previously worked as a former physics and math tutor at Los Medanos College for STEM majors. She also has previous experience working with middle and high school students as a private tutor. Susana formulates her lessons to best suit the student's individual needs. Susana believes students need repetition, encouragement, and constant participation in order to feel the desire to learn. She also believes that learning is a physiological activity which involves the body as a whole. Susana loves drawing and hiking as she enjoys being outdoors in nature. She has run the Mt. Diablo Summit twice. Susana teaches math, science, and foreign language.
Will Ranney, B.A.
Will joined Tilden’s faculty as a math, science, and humanities teacher in 2022. Will majored in Philosophy at UC Berkeley after having achieved his Associates degree in Chemistry. Will had previous experience as a tutor.
Anthony Sabatini, B.A.
Anthony graduated from the University of San Francisco with a Bachelor of Arts in History. Prior to coming to Tilden in 2021, he worked at the Museo Italo Americano as a research assistant and for two years with Pleasanton Unified School District. During that time, Anthony tutored AP history. He is a lifelong learner and hopes to share that with the students at Tilden.
Christine Schreck, B.A.
Christine is a Bay Area native who received a BA in American Studies and Peace Studies from the University of Notre Dame. She previously taught at a small Catholic high school before coming to Tilden in 2019. In the classroom, Christine enjoys helping students think critically and make connections between the concepts on the page and their lives. Outside of the classroom, Christine enjoys cheering for the Fighting Irish, writing, movie comedies, and trivia contests. Christine teaches humanities at Tilden.
Geoff Taylor, M.A.
Geoff is an East coast transplant who dreams of never leaving the West coast. He has an M.A. in Anthropology from U.C. Berkeley and worked as an archaeologist in California and Peru. Prior to joining Tilden in 2023, he was teaching Social Science sections and writing courses at UC Berkeley. He has a great love of History, Sociology, as well as Earth and Biological Sciences. Geoff can be found in his off-time hiking, trying new recipes, petting cats, and searching bins at his local comic shop.
Cristian Vera B., B.A.
Cristian was born and raised in Viña del Mar, Chile, a city by the beach. There he obtained his degree in Education and a major in English Pedagogy at Saint Thomas University. Cristian has always been a very passionate person, especially in sports and music. During his childhood, he was part of his high school’s soccer team and was awarded as top scorer of the tournaments multiple times. Cristian also taught himself to play guitar and performed in a band. At the age of 22, he became an English Teacher. One week after his graduation, he started working as a head teacher of a 6th grade class at a very prestigious school from his hometown. After three years of teaching English as a foreign language, Cristian moved to the United States where he has been working as a Spanish teacher and tutor. He joined the Tilden faculty in 2015. Cristian is a very dedicated teacher who focuses his teaching style on helping students believe in themselves by using their strengths and working hard to improve their areas of need. As a Tilden Prep Spanish teacher, he is willing to give a 100% in order to assist students in achieving their individual goals and objectives. When Cristian is not working, he loves spending time playing music, singing, playing tennis and soccer, and spending time with family.
Joseph Vincent, B.A., English and History Department Head
Joseph graduated from UCSC in 2016 with a BA in English Literature. He really enjoys teaching and that is mainly what he has been doing since graduation. Joseph’s hobbies include: hiking, playing guitar, reading novels, and learning foreign languages. Joseph became part of the Tilden faculty in 2018 where he teaches humanities.
Tamarraa Young, B.A.
Tamarraa is a recent college graduate from U.C. Santa Cruz who majored in History with an emphasis on South East Asia and the Pacific. She loves studying and teaching global history and is passionate about learning and teaching history to students in a way that they will relate to and find exciting and fun. Tamarraa looks forward to working with the students, their families and staff here at Tilden.
"I wish that traditional schools would look at the Tilden model, so that more kids would have a chance to succeed at school."Tilden Parent