Can I add a SODIMM to a laptop with soldered RAM to reach 32GB?

Probably, if your laptop’s SODIMM slot supports a 16GB module and the total 32GB is within the system’s maximum. The soldered 16GB stays put; you’re just adding another stick. But check your exact model’s specs first—some cheap or older laptops cap the SODIMM at 8GB or have BIOS limits. If the slot is already occupied, you can swap it for a larger module instead.