Thanks to the Hubble Space Telescope, combined with major ground-based facilities and gravitational lensing (“cosmic telescopes”), we have entered an era in which stellar clusters can be identified at cosmological distances. The James Webb Space Telescope (JWST) is now transforming this field -- and, more broadly, our view of the early Universe. With its exceptional sensitivity and angular resolution at infrared wavelengths, JWST, when coupled to strong gravitational lensing, can isolate individual star clusters even within the first half 0.5 Gyr of cosmic history. This lensing-enhanced spatial contrast enables the identification of candidate progenitors of present-day globular clusters and places them in the context of key questions, from the sources of ionizing photons during reionization to the emergence of extremely metal-poor (possibly near-pristine) star formation, and the possible connection to black-hole seeds. Looking ahead, ground-based facilities in the 2030s equipped with extreme adaptive optics (AO) -- most notably the ELT -- will consolidate these studies and push to even finer physical scales. The synergy between space and ground-based facilities will thus open an unprecedented window on the earliest stellar systems, connecting parsec-scale star formation to the assembly of galaxies and black holes in the reionization era.

James Webb Space Telescope (JWST) has opened a new window into the early universe, enabling sensitive, high-resolution images of the near-infrared sky and spectroscopy of faint, distant sources. The JWST Advanced Deep Extragalactic Survey (JADES) is a collaboration of the NIRCam and NIRSpec GTO teams pooling over 750 hours of JWST time to conduct an ambitious study of galaxy evolution in the Great Observatories Origins Deep Survey GOODS-South and GOODS-North fields. I will discuss exciting results from JADES observations about discoveries in the distant (z>12!) universe that provide new insight into the process of early galaxy formation and cosmic reionization. We discuss how our new constraints on star formation and galaxy growth at the very earliest times are rewriting the story of how the first galaxies form and evolve.

One of the most surprising results coming out of the first years of science operations with JWST is the unexpectedly high abundance of actively accreting black holes in the early Universe. Compared to the local population, many of these early black holes appear to differ in various aspects, such as their relation to their host galaxies or their multi-wavelength properties. These observational findings challenge our understanding of the past evolution of present-day supermassive black holes, and provide new ways to constrain theoretical models of black hole formation and growth. I will give an overview of recent observational results on massive black holes in the first few billion years, driven by the unprecedented capabilities of JWST to explore cosmic dawn, and with a focus on results from the GTO and GO NIRSpec-IFS surveys GA-NIFS and BlackTHUNDER.