35 Pages Posted: 8 Sep 2025 Date Written: August 31, 2025 Abstract We study whether generative artificial intelligence (AI) constitutes a form of seniority-biased technological change, disproportionately affecting junior relative to senior workers. Using U.S. résumé and job posting data covering nearly 62 million workers in 285,000 firms (2015-2025), we track within-firm employment dynamics by seniority. We identify AI adoption through a text-analysis approach that flags postings for dedicated "...