When I started my first job, I was shocked at the amount of racial self-selection there was. Although the company itself was diverse, many teams were 80%+ white

When I started my first job, I was shocked at the amount of racial self-selection there was. Although the company itself was diverse, many teams were 80%+ white/Chinese/Indian. If you looked closer you saw that they had all gone to the same schools (albeit in different years or even decades) or had worked together previously. This wasn't a top-tier company, so my theory was that candidates with options went elsewhere, while those without options stayed here and hired people like themselves. I could easily see the same thing happening at a place like Oracle.