I know someone who works on this in Meta. His resume is computer science heavy, with a masters in Machine Learning. On the previous experience side, before getting into Meta, he had about a decade working as a Software Engineer with Machine Learning system in multiple languages, such as Go, C++ and Python.

To get the job he applied for a spot I'm Software Engineer applied in Machine Learning, he went through the multiple step interview process, and then when he got the job he did a few weeks of training and interviewing teams. One of the teams in charge of optimizing ML code in Meta picked him up and now he works there.

Because of Meta's scale, optimizing code that saves a few ms or watts is a huge impact in the bottom line.

In sum:

- Get a formal education in the area - Get work experience somewhere - Apply for a big tech job in Software Engineer applied with ML - Hope they hire you and have a spot in one of the teams in charge of optimizing stuff