One of Lennard's notable endeavors is his involvement in the Ideenschmiede Hamburg, where he serves as a podcast host for the "Planting Seeds" podcast. The podcast aims to explore the innovation landscape of Hamburg and highlight offers, people, and organizations that are of interest to students in the area. Lennard also co-founded the Ideenschmiede, a student organization that fosters exchange and networking opportunities in the field of innovation and entrepreneurship.
Lennard is a University Innovation Fellow at the Hasso Plattner Institute of Design at Stanford (d.school). This program empowers students to become leaders of change in higher education, and Lennard collaborates with fellow fellows from around the world to create new opportunities and transformative learning experiences for their peers.
Additionally, Lennard has served as the Chairman of the Board at Enactus Hamburg, an organization that develops social innovations and implements them in various projects, with the aim of contributing to the realization of the 17 SDGs. He has also been a member of the Innovation Ressort and an Information Technology Specialist at Hamburg University of Technology.