In Spring Semester 2019 I gave a class on Spin Geometry at the university of Zurich.
Spin Geometry is the study of Spin and Clifford structures on manifolds. Its roots lie in the study of matter fields in quantum field theory, but it has many beautiful and deep connections to geometry, topology, and analysis.
The UZH webpage of the course is here
I typed a set of Lecture Notes available on arXiv.
A (very small and non-exhaustive) selection of additional references is:
H. Blaine Lawson & Marie-Louise Michelsohn, "Spin Geometry", Princeton University Press, 1990
D. Salamon, Spin Geometry and Seiberg-Witten invariants, 1996 (available online)
Pavel Etingof's lecture notes on representation theory, available online here