Developing educational experiences, which should be also engaging and interactive is a challenging task. Doing so on a platform, namely VR, which is constantly redefined and requires developers to explore interesting but intuitive forms of learning interaction is even more tough. Additionally, developers need to consider the requirements of two very different stakeholders - namely, learners and educators - while considering aspects such as fast onboarding, scalability in classrooms environments, security, and safety. This talk discusses lessons learned from developing the interactive VR learning platform "Maroon", which is currently introduced and evaluated in highschools. The talk will mainly analyze the challenges of designing, prototyping, and implementing an educational VR experience for learning STEM fields (such as physics) under significant budget and workflow constraints and discusses first experiences integrating such a platform in a classroom environment and iterating design workflows with young students in developing such an experience.