Recent demonstrations of exponential error suppression in quantum computers and sustained growth in global investment signal quantum computing's entry into the Age of Scale. We stand at a pivotal moment where quantum systems architecture becomes essential for transforming small-scale prototypes into practical, large-scale implementations. In this talk, I present system-driven approaches that guide the design of scalable quantum computing systems through integrated application- and hardware-aware optimizations. I demonstrate how compiler-level innovations for quantum Hamiltonian simulations dramatically reduce resources needed for quantum chemistry applications. I then showcase software-based strategies for mitigating dynamic hardware defects, providing elegant alternatives to costly hardware solutions. These examples illustrate how quantum systems research accelerates our path toward million-qubit systems by creating critical connections across the quantum computing stack. Looking forward, I outline future research directions for quantum systems architecture that will be crucial for realizing the transformative potential of practical quantum computing at scale.