Lead Detection & Response Platform Engineer at CoStar Group in VA Arlington

Job description

Lead Detection & Response Platform Engineer Job Description Overview CoStar Group (NASDAQ: CSGP) is a leading global provider of commercial and residential real estate information, analytics, and online marketplaces. Included in the S&P 500 Index, CoStar Group is on a mission to digitize the world’s real estate, empowering all people to discover properties, insights and connections that improve their businesses and lives. We have been living and breathing the world of real estate information and online marketplaces for over 35 years, giving us the perspective to create truly unique and valuable offerings to our customers. We’ve continually refined, transformed and perfected our approach to our business, creating a language that has become standard in our industry, for our customers, and even our competitors. We continue that effort today and are always working to improve and drive innovation. This is how we deliver for our customers, our employees, and investors. By equipping the brightest minds with the best resources available, we provide an invaluable edge in real estate. In this role, you will own and engineer the platform that CoStar Security uses to triage alerts and respond to incidents. That platform covers the SIEM, XDR, SOAR and case-management tools, and the integrations, automation and content that connect them. You will define how alerts are triaged, investigated and escalated, and then build those processes into the platform so they run the same way every time. You will also explain security concepts and decisions clearly to technical and non-technical audiences across the CoStar Enterprise. This is not a tool administration role, and it is not a software engineering role. You will set the standards for triage and incident response, measure how well the platform supports them, and improve both the process and the platform based on that data. You will mentor analysts and engineers so they can design and automate their own work. You will also coordinate incident response across the business. The successful candidate understands security operations well enough to define how the work should be done, and has the engineering skills to make the platform do it. This position can be located in Arlington or Richmond, VA and is in office Monday through Thursday and work from home on Friday. Responsibilities Own the alert triage process: define how alerts are classified, enriched, prioritized, investigated, escalated and closed, and write these as standards that analysts can follow and that can be audited. Build those processes into automation: SOAR playbooks, enrichment pipelines and case-management workflows that remove repetitive analyst work and make handling consistent. Run the detection and response stack (SIEM, XDR, SOAR, case management) as a platform, keeping its configuration, content and integrations under version control with peer review, testing and automated deployment. Measure triage and response performance (alert volume, true and false positive rates, time to triage and contain, and automation coverage) and use the data to decide what to tune, automate or retire. Work with detection engineering and threat intelligence so every new detection ships with triage guidance, enrichment and response actions, and lessons from triage feed back into tuning. Evaluate AI- and LLM-assisted triage, enrichment and case summaries, and adopt them only where they measurably cut analyst effort, with human review and defined guardrails. Coordinate incident response across business units: lead significant incidents, coordinate technical, business and legal stakeholders, and follow post-incident corrective actions through to completion. Maintain the Incident Response Plan and run quarterly tabletop exercises, turning the findings into updated playbooks and automation. Mentor and develop analysts and engineers in process design, investigation methods and automation; review their playbooks, queries and code so the team can build its