It is expected that education, professional skills, and experience play the most important roles in hiring decisions. Oftentimes, the reality looks different. In collaboration with the Swiss State Secretariat for Economic Affairs, we determined whether immigrants are discriminated against, and the factors that contribute to discrimination. Previous research on discrimination has relied upon correspondence studies, which are often expensive, interfere with actual hiring, and limited to few applications and occupations. By contrast, our method, which analyzes the entire search process on the job platform, allows for the study of discrimination across different professions and points in time. We were able to show that, on average, immigrant job seekers were 6.5 percent less likely to be contacted than Swiss job seekers with otherwise identical characteristics. Furthermore, discrimination against immigrants depends, among other things, on the time of day. Although discrimination is a structural and societal problem that is reflected across the labor market, this and other studies on discrimination can help develop strategies to increase equal hiring opportunities.