Self-gravitating systems -- such as star clusters, stellar discs, and dark matter halos -- are rich with dynamical phenomena. They exhibit both resonant (long-range) and non-resonant (short-range) dynamics, with unclear transition regimes. The coupling of linear response theory, kinetic theory, quasilinear theory, and N-body approaches for studying self-gravitating systems is now within reach, owing to recent theoretical breakthroughs. This workshop will bring together dynamicists with expertise in all these areas for a direct comparison of techniques.