Cosmology from CMB and LSS with new and old data

Cosmology is entering a new high precision era with the next generation CMB polarization experiments and galaxy surveys (Simons Observatory, CMB-S4, Euclid, Rubin).  While waiting for these new data, we can prepare for the challenges that lie ahead looking at the current (or previous) generation of data that in new ways. 
QUaia is a new full-sky high-redshift quasar catalog containing 1.5 million objects with estimated redshift derived from the Gaia DR3 quasar candidates. I this talk I will present the work that went into the creation of the catalog using unWISE, SDSS data and a machine learning approach, as well as its decontamination from stars and dust extinction. I will then present the recent cosmological results based on the cross-correlation of QUaia and CMB lensing measurements of Planck. I will focus on the implication of these results for the S8 tension and local primordial non-Gaussianities. 
In the second part of my talk I will focus on additional probes of primordial non-Gaussianities at ultra small scales that can be extracted from archival data from the COBE/FIRAS mission and modern data analysis techniques. I will then show how such data can also inform us on baryonic physics and galaxy formation.