The first three billion years of cosmic time were the prime epoch of galaxy formation. Characterising galaxies at this epoch is therefore crucial to achieving a major goal of modern astrophysics: to understand how galaxies such as our Milky Way emerged from the primordial density fluctuations in the early Universe and how they evolved through cosmic time. Recent major international investments in observing facilities such as the Atacama Large Millimetre Array (ALMA) and the James Webb Space Telescope (JWST) promise to provide the next leap in our understanding of this topic. This volume gathers the scientific contributions to the International Astronomical Union Symposium 352, which was devoted to this topic. The community of theoretical and observational experts discuss how we can make the most of ALMA and JWST synergies in advancing our understanding of galaxy evolution in the young Universe.