Instructional Leadership Team



JWJames Willett

Senior Assistant Principal of Instruction

Mr. Willett was born in a small town in the outback of Australia where he spent his school years. Upon graduating from high school, he attended the University of Newcastle, balancing his love of mathematics with his love of sports and travel. Since becoming a teacher, he taught in both England and Australia before joining the MESA team in 2016. In his spare time, you will find him searching the country for amazing outdoor activities.












Krystal Mieschberger

Assistant Principal of Instruction

Ms. Mieschberger, otherwise known as "Ms. Mish" has been at MESA since 2015! Before moving to Brooklyn, Ms. Mish grew up in Suffolk County, Long Island. During her time there she graduated from Hofstra University with a double major in both Mathematics and Mathematics Education. Since 6th grade, Ms. Mish has been inspired to be a mathematics teacher and has continued to follow that dream by teaching, coaching other teachers & furthering her own education. Ms. Mish graduated with her Master's Degree in 2017 from Touro University where she also served as an adjunct professor. Ms. Mish is passionate about all things education and loves watching MESA students evolve not only themselves but our schools' visions. When Ms. Mish is not at MESA, you can catch her enjoying a fabulous meal or playing with her dog and kitten, Lexi & Ollie!






Amy Polanco

Director of Student Supports 

Ms. Polanco was born in Brooklyn, NY, but was raised in Lawrence, MA. She attended Umass Dartmouth and earned a BA in Sociology and a minor in African American studies and has Master of Education from Umass Boston. In her free time she enjoys sharing spoilers to her friends and family. Let just say they do not appreciate it. She is a dog mom to 2 pups Milo & Chaos. She also enjoys spending time with her family and friends, trying new foods and exploring the city. Her goal is to travel through all of Central and South America by 2025.









JSJohn Sullivan

Director of Teacher and Student Development

Mr. Sullivan grew up on the beaches of Central New Jersey (no he did not go to high school with any cast members of the Jersey Shore). He has recently moved back to the NYC area after five years of teaching at a charter school in Massachusetts. Prior to that, he was a founding teacher at the Williamsburg Charter High School. In his free time, he enjoys going on day trips and adventures with his wife and two sons. He enjoys hiking, snowshoeing and having a healthy obsession with meteorology. Urban planning, architecture, street design, and neighborhood observations fill the rest of what little time he has left each day. As a huge believer in what communities can accomplish, cooperation and compassion, he is very excited to be a part of a team that displays so much of both!




STSpencer Tibbals

Director Of Humanities

Mr. Tibbals is New York City born and raised - a proud product of the NYC public education system. He attended the University of Michigan for his undergraduate degree, where he double majored in Political Science and English. After undergrad, Mr. Tibbals came back to his hometown in NYC to teach English through Teach For America. During his two first years of teaching, he earned his master's degree in the Arts of Teaching at Relay Graduate School of Education. He continues to teach English to 10th graders and leads the English Department here at Mesa. In his free time, Mr. Tibbals loves watching, playing, talking, and breathing basketball.