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Leadership and Student Success Team

Renata Joseph

Renata Joseph, CEO and Co-Owner of MJ Test Prep, has spent more than 20 years helping build MJ into one of the most respected educational and test preparation centers in the Philadelphia area. With a Master’s Degree in Education and additional coursework in business, Renata combined her passion for student growth with a strong understanding of how to create an educational model that is both academically rigorous and deeply supportive for families. Organized, methodical, and pragmatic, Renata helped transform MJ Test Prep from an idea into a highly structured and thriving educational center. As the company grew from a home office to multiple locations, she played a central role in creating the nurturing, student-focused environment MJ is known for today — a place where students can study, collaborate, build confidence, and develop a strong sense of purpose and autonomy. Renata has built much of the operational and educational infrastructure behind MJ Test Prep, streamlining systems, curriculum support, scheduling, communication, and student accountability so instructors can focus on what matters most: teaching and mentoring students. She believes that strong preparation is not simply about achieving high scores, but about helping students develop discipline, confidence, independence, and long-term academic resilience. In addition to her professional experience, Renata brings the perspective of a parent. Her three daughters all went through the MJ Test Prep program and graduated from highly competitive universities, including The Wharton School, University of Pennsylvania School of Engineering and Applied Science, and Massachusetts Institute of Technology. Having personally guided her own children through the pressures of academics, testing, and college admissions, she understands both the academic and emotional side of the process from a parent’s perspective. Over the years, Renata and the MJ team have worked with thousands of students and families through the college admissions process. She believes that every student can grow with the right structure, accountability, encouragement, and individualized support, and that meaningful achievement comes from helping students realize they are capable of more than they initially believed possible.

Juliet

Juliet Popiel, our Director of Marketing and Relations, has been with MJ Test Prep since 2018. With a background in Physics and Mathematics, Juliet has a deep understanding of the analytical thinking and problem-solving skills that underpin success on standardized tests. Her passion for education began long before stepping into a leadership role, and she is deeply committed to helping students discover their potential while building confidence and independence as learners. Juliet first joined MJ Test Prep while in college, working at the front desk and supporting students, families, and instructors behind the scenes. After graduating, her passion for advising, education, and student development led her to take on a much larger role within the organization. Today, she works closely with families to help students build long-term academic plans while collaborating with the MJ Test Prep team to develop individualized curricula that align with each student’s goals, strengths, and areas for growth. As a member of the leadership team, Juliet serves as one of MJ Test Prep’s primary contacts with school counselors and educational partners. She works closely with schools, families, tutors, and administrators to ensure students receive thoughtful guidance and personalized support throughout their academic journey. Whether helping a family navigate SAT preparation, academic tutoring, executive function coaching, or long-term educational planning, Juliet is committed to creating a supportive and encouraging experience for every student. Juliet also plays a major role in MJ Test Prep’s outreach and marketing efforts. Using years of student performance data, parent feedback, and real student outcomes, she helps communicate the opportunities MJ Test Prep provides for score growth, academic development, and long-term student success. Her understanding of both the educational and emotional side of the process allows her to connect with families in a meaningful and authentic way. Juliet believes that meaningful learning happens when students understand not only how to solve problems, but why concepts work. Her approach emphasizes curiosity, critical thinking, and the development of skills that extend far beyond any single test.

Claudia

Claudia Berthold, our Student Services & Operations Manager, has been part of the MJ Test Prep family long before joining the team professionally. A graduate of The Agnes Irwin School, Claudia first came to MJ Test Prep as a student, where she worked with Dr. Matt Joseph and achieved outstanding SAT scores herself. She later graduated Summa Cum Laude from Miami University with a degree in Education. Because Claudia experienced the program firsthand, she brings a deep understanding of the dedication, discipline, and strategy required to succeed in rigorous high school programs and the college admissions process. She has always been passionate about education and student growth, and she chose to bring that passion to MJ Test Prep, where she plays a key role in supporting students, families, and curriculum development. Claudia is one of the driving forces behind creating lesson plans and helping “beautify” the curriculum — making challenging material more approachable, student-friendly, and engaging while still maintaining the rigor needed for top score improvement. She closely monitors student progress and makes sure nobody falls behind on homework or assignments. Claudia is always finding ways to support students, whether that means guiding them through missed questions, helping them retake difficult sections, or scheduling time for students to come into the office to complete work in a quiet and focused environment. Her warmth, organization, and genuine investment in student success make her an invaluable part of the MJ Test Prep team.