It's important to meet diverse candidates where they hang out — tapping into the same sources over and over again may lead to diminishing returns as you'll be tapping into the same group of potential talent. There are several job boards and communities that promote diversity in tech, and many of them feature job matching, platforms, and boards as part of their offering.
This is a non-exhaustive list of job boards (besides the standard Indeed, Wellfound (formerly AngelList Talent), and Triplebyte boards) that we recommend checking out and posting jobs on.
OutProNet is a diversity-based jobs board
Hire Autism is a jobs board for those on the autistic spectrum
Recruit Disability is a jobs board for people with disabilities
Pink Jobs is a jobs board for LGBTQ+ people
TransWork is a jobs board for transgender people
Include.io is a job board for diverse people in tech
PowertoFly is a job board for diverse people in tech
Women Who Code is a job site for engineers who identify as women
Elpha is a community for women in tech
POCIT is a job board for people of color in tech
For more diversity based job boards check out this piece.