The student will participate in the exploitation of the parametric map-based pipeline developed during the first internship, applied to the Simons Observatory data sets, with the goal of constraining the CMB E-modes on the largest angular scales. The student will work and collaborate closely with the rest of the SciPol team at APC. He/She will base his/her implementations using the JAX-powered framework that is being developed, opening the student to High Performance Computing and the use of GPUs.