Hiring international talent is a critical piece of the company culture at Duolingo, the $700 million language learning app company founded by two immigrants. In fact, most Pittsburgh technology companies agree that attracting and retaining talent from outside the U.S. is a vital part of the city’s progress. Yet, Christine Raetsch, head of people at…

At the self-driving firm Argo AI, at least 10 percent of the staff work under visas or hold a green card. The workforce at Downtown’s SDLC Partners, an information technology consultant, is made up of about 28 percent foreign nationals. According to Katherine Huber, vice president of human resources, that figure makes the company Pittsburgh’s largest sponsor…