Simulators are an essential component of quantum computing frameworks in which they play the role of backends complementary to quantum hardware. Here we discuss two aspects of the interaction between simulators and the rest of the quantum computing system. First, we demonstrate the advantage of co-developing simulators and compilers by proposing a specialized compiler pass to reduce the simulation time for arbitrary circuits. Second, we increase the realism of the simulations by describing gates not as unitary matrices, but as general quantum channels. In this way, device characterization like process tomography can be readily used in simulation. In both cases, we present concrete implementations within the Intel Quantum Simulator, an open-source, high-performance, state-vector-based simulator.