Chief Executive Officer
Lisa Margosian has served as Chief Executive Officer of Achievement First since 2022, initially in an interim capacity before stepping into the permanent role. She brings more than 40 years of leadership experience across the financial services, education, and nonprofit sectors.
Prior to joining AF, Lisa held senior roles at KIPP and Ascend Charter Schools, including Interim CEO at Ascend, Chief Program Officer at the KIPP Foundation, and Chief Customer Officer at Girl Scouts of the USA, where she led national programming for young women across the country.
Throughout her career, Lisa has been committed to creating the conditions for young people to access an excellent education — and the opportunities that come with it. A strong believer in servant leadership, she sees her role as “setting the table” so that AF’s talented team can fully realize the organization’s student-centered mission.
Lisa lives in New York City and is the proud mother of two adult children. Outside of work, she enjoys entertaining family and friends and spending time outdoors year-round.
Chief Equity Officer
LaNelle Alexander serves as Chief Equity Officer at Achievement First, bringing nearly 20 years of experience leading organizational development and equity initiatives across nonprofits, higher education, and the private sector. She has dedicated her career to advancing equity and dismantling systemic racism by fostering healthy, inclusive organizational cultures.
Previously, LaNelle served as inaugural Head of DEI in the private sector, where she executed a multi-year DEI-AR plan, coached senior leaders, and aligned organizational culture with mission and values. Earlier, she was on the executive team at buildOn, an international nonprofit as their inaugural Vice President of HR and founding Global Director of EDI.
LaNelle is a mission-driven leader, facilitator, and certified leadership coach who embeds equity and justice into organizational systems. She holds a BA in Organizational Behavior and Change Management from New York University, is an ICF-certified coach, and maintains SHRM-CP and CDP certifications. She lives in Connecticut and serves on the boards of buildOn NY and HOPE Worldwide’s CT Chapter.
Chief of Support Services
Tiffany Bostic is Chief of Support Services at Achievement First, where she leads efforts to strengthen supports related to student mental health, special education, multilingual learners, school culture, student discipline, and social-emotional learning. A licensed clinical social worker, she is passionate about improving student outcomes and ensuring young people have the support to thrive.
Since joining AF in 2020 as Director of Social Work, Tiffany has expanded the scope of student services significantly. Under her leadership, the number of mental health clinicians grew from 48 to 65, a Senior Director of Social Work role was created, and a clinical supervisor program was launched to build a sustainable leadership pipeline for social workers and school counselors. She also codified our crisis response protocols and clinical support staff professional development systems, increasing capacity and collaboration across schools.
Previously, Tiffany worked as a middle school social worker at Bedford Stuyvesant Collegiate, where she expanded services, created community partnerships, and founded a male mentorship program. She earned her BA from Clark Atlanta University and her MSW from Howard University. She lives in Brooklyn and enjoys biking, trying new restaurants, listening to podcasts, and traveling.
Executive Director, New York
Kristin Damo serves as Executive Director for Achievement First New York, bringing nearly two decades of experience in education. She joined AF in 2021 and previously served as Regional Superintendent, supporting both elementary and middle schools.
Before joining AF, Kristin was a middle school principal at Success Academy Charter Schools, where she prioritized rigorous academics and a joyful school culture. Earlier in her career, she taught AP high school courses, worked as an instructional coach, and was a Teach Plus leadership fellow.
Kristin’s leadership is grounded in the belief that strong teaching and leadership can transform student outcomes. She is deeply committed to ensuring that all students experience academic excellence and a strong sense of belonging.
She holds a B.A. from Carleton College and an M.A. from Teachers College, Columbia University. Kristin lives in Brooklyn with her partner, their children, and their dog, Thor, and enjoys exploring the city with her family.
Interim Chief Financial Officer
Dr. Omar Mayyasi comes to Achievement First with over two decades of financial and operational experience in education. As CFO, Omar leads Team Finance in overseeing the organization’s fiscal health, positioning it for sustainable growth and impactful educational outcomes. Omar brings a wealth of expertise in financial management, strategic planning, and operational efficiency, underscored by a commitment to educational access and student success. His approach to fiscal management is grounded in data analytics and stakeholder feedback, ensuring that financial strategies align with the institutional mission and strategic objectives. Omar’s passion for education is rooted in his belief in the transformative power of education to foster social justice and racial equity.
Prior to joining Achievement First, Omar held leadership roles at various education institutions, including an independent school, a community college and a private higher education institution. Omar earned a Bachelor’s degree in Business Administration from the American University of Beirut, and a Doctorate in Economics and Education from Columbia University. He is also a Certified Public Accountant, licensed in New York and Florida. Omar resides in Westchester County with his family, where he is actively involved in the community, coaching youth soccer and serving as a trustee on the board of education in his district.
Chief of High Schools
Dumar Paden serves as Chief of High Schools at Achievement First, leading the vision and strategy for improving high school results, monitoring progress, and building long-term program design.
With nearly two decades of experience as an educator and school leader, Dumar brings deep expertise in building successful high schools that prepare students for college, career, and beyond. Since joining AF, Dumar has served as Academic Dean at AF University Prep HS, Principal of AF Brooklyn HS, and Regional Superintendent. As Principal, he guided AF Brooklyn HS through the height of the pandemic while raising AP performance, improving organizational health, and significantly reducing suspensions.
Dumar’s leadership is rooted in equity, resilience, and partnership with school teams. Born and raised in Brooklyn, he was the first male in his family to graduate from college. He holds a B.S. from SUNY Albany and an M.S. from Grand Canyon University.
Chief Strategy Officer
Michael Rabin serves as Chief Strategy Officer at Achievement First, where he leads long-term growth and strategic planning across the network. He joined AF in 2022 as Associate Chief of Staff and brings over 15 years of experience in education.
Michael began his career as a middle school teacher before stepping into school leadership as a Founding Assistant Principal and Principal. He later served as Associate Director of Schools at Rocketship Public Schools in Washington, D.C., supporting leaders to strengthen instruction and expand their impact.
Throughout his career, Michael has focused on scaling the reach of high-quality public charter schools, always grounded in student outcomes and community needs. He believes deeply in collaborative leadership and working alongside others to pursue ambitious goals in service of students and families.
Originally from Chicago, Michael now lives in Fairfield, Connecticut, with his wife, their daughters Devon and Blair, and their yellow lab, Clementine. He’s a lifelong Chicago sports fan and an aspiring golfer.
Chief of Development
Aaron Obrochta serves as Chief of Development at Achievement First, where he leads philanthropic strategy and public grant funding to support 15,000 students across three states. He brings nearly two decades of leadership experience spanning the military, education, and nonprofit sectors.
A former Naval Officer and Navy helicopter aircraft commander, Aaron transitioned to senior talent strategy roles at Ascend Public Charter Schools, where he helped steer organizational change with a strong focus on equity, culture, and impact. He’s passionate about building authentic partnerships with donors and funders to expand opportunities for students and their communities.
Aaron holds an MBA from NYU’s Stern School of Business and a master’s in Education Leadership from The Broad Center. He lives in New York with his wife and three boys and enjoys family adventures in the outdoors, rooting for his sons on the sidelines, and volunteering locally.
Executive Director, Connecticut
Amy D’Angelo serves as Executive Director of Achievement First Connecticut, bringing more than 25 years of experience in public education and leadership. Over her 17 years with AF, she has held several key roles, including founding Principal of AF Bushwick Middle School, Regional Superintendent, Chief of Middle Schools, and Chief of High Schools.
Before joining AF, Amy worked at McKinsey & Company and later entered education as a NYC Teaching Fellow. She became a NYC principal through New Leaders for New Schools. During her time at AF Bushwick Middle School, the school was recognized as the #1 public school in NYC in 2012 and earned the prestigious National Blue Ribbon School designation – milestones she attributes to an unwavering pursuit of continuous improvement and strong teamwork between the school team, students, and families.
Amy’s leadership is rooted in high expectations, collaboration, equity, and a deep commitment to keeping kids at the center of all decisions. As a regional leader, she believes in partnering with school leaders to achieve ambitious outcomes, and creating the conditions for schools to thrive. She lives in Connecticut with her husband, Renato, two children, Zarius and Samaya, and their Bernedoodle, Kai.
Executive Director, Rhode Island
Dr. Tom McDermott joined Achievement First in 2025 as Executive Director of Rhode Island, bringing nearly 20 years of experience as an educator and leader. Prior to AF, he served as Managing Director for the Northeast Region at ANet, Chief Strategy Officer for Jefferson County Public Schools in Colorado, and as both a teacher and school leader at Uncommon Schools.
Tom is especially proud of leading a community-driven strategy in Jeffco that brought students, families, and educators together to co-create a district-wide vision grounded in equity. That work helped boost graduation rates for historically underrepresented students and launched a nationally recognized innovation fund that brought student-led ideas to life.
He leads by listening first and centers coherence, equity, and shared ownership in all aspects of his work. Tom lives in Rhode Island with his wife, Lizzy, their daughters Caroline and Grace, and their bulldog, Rocco. He enjoys fly-fishing along Rhode Island’s beaches and estuaries.
Chief Operating Officer
Jason Russell serves as Chief Operating Officer at Achievement First, where he leads network-wide operations to ensure schools have the systems and resources they need to thrive. He brings over a decade of charter school operations experience, most recently as Associate Chief Operating Officer at Uncommon Schools, where he managed operations for multiple schools in both NJ and NY, serving more than 6,500 students.
Jason began his career in Brazil, working in marketing, sales, and business development before transitioning into school operations as Director of Operations at North Star Academy in Newark. He holds a B.S. in Business Administration from the University of Richmond and completed Columbia University’s Senior Leadership Program for Nonprofit Professionals.
He leads with a focus on efficiency, equity, and empowering school teams with the tools they need to stay focused on students. Jason lives with his husband in New Jersey and enjoys spending as much time outdoors as possible.
General Counsel
Mirtha Camille Sabio, Esq., serves as General Counsel at Achievement First, bringing extensive experience across public agencies, private enterprises, and advocacy work.
Prior to joining AF, she led a team of 20 at the NYC Office of Chief Medical Examiner, overseeing legal operations, records management, and quality assurance functions, and driving compliance for the largest public DNA lab in the world. Previously, she was General Counsel at the Office of the Bronx Borough President, serving under two Presidents, advising on conflict of interest issues, policy, and compliance while advancing greater MWBE investor participation as a Trustee on the New York City Employees’ Retirement System’s board, the largest municipal public employee retirement system in the United States. She also advanced civic engagement by providing technical and legal guidance to the Borough’s 12 community boards.
Mirtha’s career includes corporate counsel roles, litigation, and labor negotiations, with a proven ability to mitigate risks in complex environments. A passionate advocate for equity, she has developed programs to expand access and opportunity for underrepresented groups.
She holds a JD from New York Law School and dual BS degrees in Accounting and Marketing from NYU Stern School of Business. She also maintains professional certifications in employment law, HR management, and real estate development. Mirtha lives in New York City, serves on multiple boards, and volunteers regularly as a moot court judge.