  We derive an effective equation of motion within the steady-state subspace of
a large family of Markovian open systems (i.e., Lindbladians) due to
perturbations of their Hamiltonians and system-bath couplings. Under mild and
realistic conditions, competing dissipative processes destructively interfere
without the need for fine-tuning and produce no dissipation within the
steady-state subspace. In quantum error-correction, these effects imply that
continuously error-correcting Lindbladians are robust to calibration errors,
including miscalibrations consisting of operators undetectable by the code. A
similar interference is present in more general systems if one implements a
particular Hamiltonian drive, resulting in a coherent cancellation of
dissipation. On the opposite extreme, we provide a simple implementation of
universal Lindbladian simulation.
