The NHR Workshop: Scaling Complexity was successfully held on December 2–3, 2024, at the Zuse Institute Berlin (ZIB). Organized by Sarah Wolf and Steffen Fürst (FU Berlin) and Natasa Djurdjevac Conrad (ZIB), and sponsored by NHR, the event gathered over 30 participants to explore high-performance computing (HPC) in Agent-Based Modeling and Complex Networks. The workshop featured five invited talks, a panel discussion, and nine poster presentations, fostering vibrant discussions on computational challenges and advanced methodologies for complex systems. A hands-on session on Vahana.jl provided practical training in scalable ABM simulations, equipping researchers with essential tools to to apply HPC effectively in their work.