Getting a PhD internship in RL/Robotics at big tech firms?

I finished my B.S. and M.S. in aerospace engineering w/ a focus in optimization, control, and deep learning. I'm an upcoming PhD student doing research in RL/robotics/optimization. I wonder how hard it is to get an internship in RL/robotics at big tech firms such as Tesla(Optimus robot), Nvidia (autonomous driving), etc? How do the recruiters evaluate resumes from PhD students? Thanks!