This week, we are excited to profile Isy Gabriela Castillo, Chief External Officer for YES Prep Public Schools, an extraordinary leader inspiring growth in charter schools.
Isy Gabriela Castillo grew up in Guadalajara, Mexico, where her parents really believed in the power of education. They always encouraged their kids to aim for higher degrees in the United States.
“I understood the power of education very early on,” Isy said. “I was very lucky to have parents that were big supporters of our education throughout.”
Inspired by her parents’ dedication, Isy made her way to the United States to pursue higher education.
She started out working with the Hispanic Chamber of Commerce and community groups before joining KIPP Texas, where she found her passion for charter schools.
Isy played a key role in merging four KIPP Texas Regional Networks into a single nonprofit that now supports over 27,700 students across 52 campuses in cities including Austin, Dallas, Fort Worth, Houston and San Antonio.
A scaling and operations expert, Isy transitioned to YES Prep Public Schools to support the growth of the network. She’s had tremendous success—YES Prep reported record student enrollment for the 2024-25 school year.
“My skill set and my passion are just beautifully all connected in this new venture,” said Isy.
Charged with Growth
As Chief External Officer, Isy handles advocacy efforts, oversees marketing and communications, drives community engagement, leads development projects, and strategizes how to recruit students. YES Prep has 24 schools serving more than 20,000 students from pre-K to 12th grade throughout Houston. It’s one of the fastest-growing and highest-performing charter school networks in the U.S.
To understand why YES Prep is so successful in a time when schools are battling low enrollment numbers, Isy says you must go back to the beginning of YES Prep. It started as a youth engagement project aimed at encouraging young students to give back to their community, and this spirit of caring continues to thrive today.
“We are a community that cares for families and the communities we serve,” Isy emphasizes. This strong trust has allowed YES Prep to expand and effectively catch students along their educational journey. Although it began as Project Y.E.S. (Youth Engaged in Service) in 1995, YES Prep was first awarded a charter from the state of Texas in 1998. It has built trust within Houston for decades.
YES Prep has primarily focused on secondary education, ensuring students are ready for college, which is a core part of their mission. But in the last four years, they’ve also connected with elementary school families. This academic year was the first year YES Prep had fifth graders graduating to sixth grade.
“Hearing the confidence that our sixth graders have is really inspiring,” said Isy, noting that engaging younger families is different. “The opportunity of us finishing our pipeline… it makes me really proud and grateful to lead that work.”
Their ability to create a seamless educational path is a big reason for YES Prep’s success.
Isy points out that many students at Yes Prep are first-generation graduates.
“They come from parents that didn’t get that opportunity for a high-quality education, so with our support, they’re able to fulfill a dream for their parents and themselves,” said Isy. “College is the north star for most of our families.”
Looking ahead, Isy imagines creating a full Pre-K to 12 pipeline for YES Prep in Houston, so every student who walks through their doors has a chance to succeed at YES Prep. Her hope is a unified approach within the pipeline between elementary and secondary school systems.
Education without barriers
YES Prep also has a strong Hispanic student population and offers a fully bilingual program starting in Pre-K, ensuring language isn’t a barrier.
“We’re able to not allow a language barrier to block the educational attainment of our students, regardless of their nationality,” Isy explained.
Their approach to literacy supports students’ home language while building their English skills, helping them express their thoughts in both languages. Isy’s seen this program outperform traditional multilingual education. Every YES Prep school also has a Family Association, which helps connect families with important local issues, reinforcing her belief in accessible education for everyone.
“I know firsthand what it means to live in an area that does not have free quality education programs for you and your family,” said Isy. “I had to come to a different country to find that, and so I believe that charter schools give that opportunity to all students regardless of their zip codes, and that, I think, is the north star of our work.”