The Sun is the most efficient particle accelerator in the solar system, capable of accelerating ions to energies from a few MeV to tens of GeV, and electrons from tens of keV to tens of MeV, on timescales of 100 -1000s. The accelerated electron component of solar flares contains up to 50% of the total energy released, while solar energetic particle (SEP) events contain ∼10% of the total energy of the associated coronal mass ejection (CME), for those events accompanied by a CME. How and where these particles are accelerated, and the details of the conditions that lead to such a wide range of energies remains to be fully understood. However, our ability to probe many layers of the solar atmosphere simultaneously with high spatial, spectral and temporal resolution offers unique insights, and possibilities for the future. In this presentation I will review current observations in the context of existing paradigms for eruptive flares, and discuss prospects for future instrumentation to address unresolved questions.