  I review recent progress in the NNPDF global analyses of parton distributions
(PDFs) focusing on developments contributing to its new upcoming release:
NNPDF4.0. The NNPDF4.0 determination represents unprecedented progress in three
main directions: i) the systematic inclusion of LHC Run II data at 13 TeV and
of new processes from dijets to single top distributions, ii) the deployment of
state-of-the-art machine learning algorithms, from automated hyperparameter
optimisation to stochastic gradient descent training; and iii) the complete
statistical validation of PDF uncertainties, both in the data and extrapolation
regions, by means of closure and future tests. Other methodological
improvements in NNPDF4.0 include strict PDF positivity, integrability
constraints at small-$x$, and deuteron and heavy nuclear corrections. I present
representative results from NNPDF4.0 and assess its impact on open issues such
as the light anti-quark asymmetry and the charm content of protons.
