Senior Cloud Platform Security Engineer

Senior Cloud Platform Security Engineer 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 and the NASDAQ 100, 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. CoStar builds and operates web applications related to real estate. Web applications include Apartments.com, Homes.com, Lands.com, CoStar.com, and 75 other web applications. The backbone of our product security is our product platform security environment, which consists of commercial and custom developed security controls that run within the IDE, the CI/CD system, across cloud and Kubernetes platforms, and our product edge. Our product platform security engineering group builds and operates centralized controls using infrastructure as code, scripting, and API integrations to scale security across all web applications in a consistent manner. This position is located in Arlington, VA or Richmond, VA and offers a schedule of Monday through Thursday in office and Friday work from home. Responsibilities Cloud Security and Guardrails: Enforce security posture across AWS, GCP, and Azure through preventative controls (SCPs, organization policies, IAM guardrails) and detective controls (Wiz, native cloud security services). Build detection patterns and escalation paths in partnership with incident response. Drive validation methodology and operational rigor across acquisitions and new environments. Kubernetes Platform Security: Lead workload protection strategy across EKS clusters, including runtime monitoring, admission control, network policy, and secrets management. Drive sensor coverage validation, incident response readiness, and security guardrails that scale across the portfolio. AI and Agentic System Security: Partner with product engineering on securing AI-powered features, MCP server implementations, and agentic workflows across the portfolio. Lead threat modeling for new AI surfaces, build guardrails and detection patterns for prompt injection and unauthorized tool use, and shape security standards as the company expands AI capabilities into customer-facing products. Security Automation: Integrate automated scanning tools into CI/CD pipelines, implement IaC solutions, and drive automated remediation processes. Mentorship & Collaboration: Work closely with product dev teams to provide feedback on secure coding practices, proactively guide them on risk remediation. Basic Qualifications Bachelor’s Degree required from an accredited, not for profit, in person, university or college (preferably in Computer Science, Cybersecurity or a related field). A track record of commitment to prior employers. 6+ years of hands‑on security engineering experience, with depth in at least one and meaningful exposure to others among the following domains: Securing cloud‑native environments (AWS preferred). Kubernetes platform hardening or monitoring. CI/CD pipelines, containerized application deployments, and IAC, and software supply chain security. Demonstrated track record of taking security initiatives from scoping through production rollout and operational ownership. Demonstrated ability to author scripts or IAC from scratch in either Python, PowerShell, Ansible, CloudFormation, Terraform, or similar language. Securing AI‑powered applications, including threat modeling for LLM‑based features, MCP server implementations, or agentic systems. Experience working in a software development environment with a mature CI/CD. Passion for solving complex challenges, innovating, and engaging in your work. Preferred Qualifications and Skills A self‑starter who can advance the platform security program and follow‑through ideas to completion. Experience with tools and services like AWS GuardDuty, Security Hub, EKS, OPA/Gatekeeper, Falco, Wiz, Datadog, Prisma Cloud, Orca, Upwind, Snyk, or similar. Familiarity with software supply chain security, including SBOM generation, dependency vulnerability management, build provenance, and artifact signing. Knowledge of infrastructure operations across databases, network, and system administration. Effective use of AI tools as a force multiplier for engineering work, with judgment about when AI accelerates work versus when it creates rework. Ability to communicate with different levels of leadership conveying risk and driving urgency for risk remediation. Familiarity with zero trust principles and cloud‑native access controls (e.g. IAM roles, service meshes). Ability to mentor and train team members to prioritize security efforts effectively. Hands‑on experience implementing security tools into CI/CD pipelines. Experience testing serverless cloud deployments. What’s in it for You When you join CoStar Group, you’ll experience a collaborative and innovative culture working alongside the best and brightest to empower our people and customers to succeed. We offer you generous compensation and performance‑based incentives. CoStar Group also invests in your professional and academic growth with internal training, and tuition reimbursement. Our benefits package includes (but is not limited to): Comprehensive healthcare coverage: Medical / Vision / Dental / Prescription Drug Life, legal, and supplementary insurance Virtual and in person mental health counseling services for individuals and family Commuter and parking benefits 401(K) retirement plan with matching contributions Employee stock purchase plan Paid time off Tuition reimbursement On-site fitness center and/or reimbursed fitness center membership costs (location dependent), with yoga studio, Pelotons, personal training, group exercise classes Access to CoStar Group’s Employee Resource Groups Complimentary gourmet coffee, tea, hot chocolate, fresh fruit, and other healthy snacks We welcome all qualified candidates who are currently eligible to work full‑time in the United States to apply. However, please note that CoStar Group is not able to provide visa sponsorship for this position. CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug‑free workplace and perform pre‑employment substance abuse testing #J-18808-Ljbffr