CoStar Group, a leading provider of real estate information and analytics, is seeking a Senior Software Engineer to join their team in Arlington, VA. This role offers a hybrid work arrangement with in-office work Monday through Thursday and remote work on Fridays. As a Senior Software Engineer, you'll have direct impact on CoStar Suite web applications that serve millions of users globally. The position requires 6+ years of experience with modern technologies like React, TypeScript, and Node.js, and offers comprehensive benefits including healthcare, 401(k) matching, and tuition reimbursement. You'll be working for a NASDAQ 100 and S&P 500 company that's been a leader in real estate information for over 35 years. The role involves designing high-performance web applications, mentoring junior developers, and driving continuous improvement through engineering excellence. CoStar offers a collaborative culture, competitive compensation, and comprehensive benefits including medical coverage, mental health support, and various lifestyle perks. The company is committed to innovation and maintaining its position as a global leader in commercial real estate information, analytics, and news.