Understanding the key drivers of cosmic reionization, an important phase transition in the history of the early Universe, is an exciting challenge in modern astrophysics. The parameters that dictate how reionization unfolds are the number density of UV photon emitting sources, the photon production rates in these sources and crucially the escape fraction of ionizing photons from galaxies into the intergalactic medium, which remains relatively unconstrained. In this talk I will present our recent work identifying galaxies that harbour stellar populations or non-thermal sources such as X-ray binaries that are capable of producing capable amounts of ionizing photons, as well as insights into Lyman continuum photon escape from star-forming galaxies. I will conclude by presenting prospects for constraining reionization in the era of JWST, focusing in particular on the NIRSpec GTO team efforts over the next couple of years.