Meet the Mostows
Sarah
Sarah is a PhD student at Duke University studying statistics. She completed her undergraduate degree at the University of Chicago with a triple major in math, statistics, and economics. Before beginning her graduate studies, Sarah spent two years at BlackRock in NYC as a financial algorithm engineer. She was a National Merit Scholar and has scored in the 99th percentile on the GRE and SAT.
Sarah has over 8 years of tutoring experience and has helped many students navigate college applications and craft compelling essays. In addition to working with middle and high school students, she has worked as a teaching assistant for university courses and has tutored college students in upper-division courses including Multivariable Calculus, Complex Analysis, and Differential Equations. With her rigorous mathematical background, Sarah uniquely offers a deep conceptual understanding of STEM topics that most other tutors cannot provide.
Areas of expertise: math, statistics, economics, computer science
Ari Mostow graduated cum laude from Northwestern University with a B.A. in English Literature. He began his tutoring career in 2021 at a large tutoring company before transitioning to private tutoring, where he has since helped students excel in standardized test preparation and guided dozens through the college application process, with a particular focus on crafting compelling Common App essays. He will be attending UCLA School of Law beginning in Fall 2026.
Ari’s background is in storytelling and communication. In addition to his academic coaching, he is a stand-up comedian and screenwriter who performs in and produces shows at Los Angeles venues, including The Comedy Store and Upright Citizens Brigade. He was a category winner in the 2025 Austin Film Festival Screenwriting Competition.
Ari draws on his comedy and creative background to keep students engaged and to help them build confidence in writing and creative expression.
Areas of Expertise: college essays, standardized test prep, writing, English literature
Ari
Gabrielle
Gabrielle is a 2026 Harvard graduate with a major in biology and a minor in statistics. During her undergraduate career, she earned numerous competitive research grants and was named a 2025 Herchel Smith Science Research Fellow. Gabrielle has been recognized as a John Harvard Scholar, placing her in the top 5% of her class.
In addition to her 7+ years of tutoring experience, Gabrielle leverages her application expertise to help students craft standout college, internship, and summer program applications. She scored a 1580 on the SAT and maintained a 3.97 GPA at Harvard.
Areas of expertise: biology, statistics, application writing