The software system is one essential and critical component in a quantum computing system. However, existing quantum software infrastructures are mainly designed for small-scale quantum computers while they cannot effectively accommodate large-scale quantum computing systems. In this talk, I will first summarize the challenges in designing quantum software systems as the sizes of quantum computer systems continue to grow. Then I will show how we can overcome this grand scalability challenge by leveraging the power of high-level operators in various important tasks, including quantum compiler optimization, quantum program testing, and so on. In the end, I will briefly introduce my work on quantum software-hardware co-design and conclude my talk with future research opportunities.