Quantum computers can solve important problems that are beyond the capability of conventional computers. Quantum computing is at an inflection point where small systems with a few tens qubits have been demonstrated and the number of qubits is expected to increase to several thousand over the coming years. As qubits are low-energy devices, they are susceptible to high error-rates (in the range of 0.1% to 1% per operation). Unfortunately, quantum error-correction incurs a significant overhead (hundreds of physical qubits per fault-tolerant qubit) and is impractical for near-term machines. Therefore, hardware errors will continue to severely restrict the length of the program that can be reliably executed on a near-term quantum computer. In this talk, I will offer a computer-systems perspective of quantum computers and then share some of our recent work that improves the reliability of near-term quantum computers with intelligent software techniques. I will also discuss the hardware support necessary to enable large- scale quantum computers.