Iresha has worked in Sri Lanka, New Zealand, Germany, South Africa, and Sweden, and collaborates with international research teams across Europe, Asia, Australasia, and Africa. She holds a PhD in Mathematics Education from the University of Auckland and has contributed to several international research projects aimed at improving mathematics education and promoting equity in learning.

Her research bridges theory and practice, with a strong focus on how students and teachers engage with mathematical ideas — particularly through digital technology, mathematical language, representation, and reasoning. She is deeply committed to supporting teachers' professional growth and to fostering inclusive, high-quality mathematics learning environments.

Iresha regularly presents her work at international conferences and serves as a reviewer for leading mathematics education journals. She is also actively involved in mentoring early-career researchers, including PhD candidates, and in developing collaborative, grant-funded projects.