I want to enter the U.S. gambling industry as a software engineer, what are the ways in?

My younger brother is currently studying Computer Science on the West Coast of the United States and is interested in software development for the gambling industry. However, he has found that job postings in this industry are not as readily available as they are in typical tech companies. After searching with keywords, most of what he found were mentions of a few major companies in the news, but their official websites did not have clear internship or full-time job postings.

His current plan is to check the member company list at the American Gambling Association and then contact them one by one to see if there are any opportunities. However, he would still like to ask for advice from those with relevant experience. In the U.S., if one wants to enter the gambling industry as a software engineer, are there more direct ways to do so? For example, which companies are known to hire frequently, or are there better job search strategies? Thank you!