  We propose a highly-scalable method to compute the statistics of charge
transfer in driven conductors. The framework can be applied in situations of
non-zero temperature, strong coupling to terminals and in the presence of
non-periodic light-matter interactions, away from equilibrium. The approach
combines the so-called mesoscopic leads formalism with full counting
statistics. It results in a generalised quantum master equation that dictates
the dynamics of current fluctuations and higher order moments of the
probability distribution function of charge exchange. For generic
time-dependent quadratic Hamiltonians, we provide closed-form expressions for
computing noise in the non-perturbative regime of the parameters of the system,
reservoir or system-reservoir interactions. Having access to the full dynamics
of the current and its noise, the method allows us to compute the variance of
charge transfer over time in non-equilibrium configurations. The dynamics
reveal that in driven systems, the average noise should be defined
operationally with care over which period of time is covered.
