Sr. Security 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 and the NASDAQ 100 CoStar Group is on a mission to digitize the worlds 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. Weve 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.

We are seeking a Senior Security Engineer with experience in Network SaaS and AI Security to help evolve and safeguard CoStars enterprise security posture across network infrastructure cloud services SaaS platforms and emerging AI systems.

This role expands upon traditional network security engineering to include SaaS security governance and AI security risk management supporting both human and machine-driven workflows. The ideal candidate brings deep technical capability strong security judgment and the ability to communicate security concepts effectively to both technical and non-technical audiences across the enterprise.

This position can be located in Arlington or Richmond VA and is in office Monday through Thursday and work from home on Friday.

Responsibilities

Network & Cloud Security

• Provide engineering expertise to ensure enterprise network changes are designed and implemented securely (on-prem and cloud).
• Audit existing network designs and infrastructure configurations and recommend improvements to security posture.
• Evaluate firewall change requests across on-premise and cloud environments.
• Design enforce and audit policies for Next Generation Firewalls (NGFW) load balancers routers switches and wireless infrastructure.
• Manage Secure Service Edge (SSE) platform
  

SaaS Security

• Partner with application owners and third-party risk teams to review SaaS security architecture and control effectiveness.
• Operate and tune SaaS security tooling (e.g. CASB/SSE capabilities) to detect risky behavior misconfigurations and data exfiltration paths.
• Define and enforce SaaS security standards for logging identity integration and least-privilege access.
• Support SaaS incident investigation and remediation efforts in coordination with legal privacy and compliance teams.
• Develop reusable SaaS security review patterns and documentation for engineering and procurement teams.
  

AI & Emerging Technology Security

• Assess security risks associated with AI platforms copilots and agent-based systems including model access controls prompt/data leakage risks and tool/plugin abuse.
• Partner with engineering teams to design security controls for AI-assisted workflows and developer tools.
• Contribute to governance models for AI usage including enforcement of network identity and data security boundaries.
• Monitor AI-related telemetry and logs to identify anomalous behavior data exposure or misuse patterns.
• Support threat modeling and risk assessments for AI integrations with enterprise systems and SaaS platforms.
• Stay current on AI security threats abuse patterns and control frameworks translating them into actionable enterprise safeguards.

Basic Qualifications

• Bachelors Degree is required from an accredited not for profit in-person university or college.
• A track record of commitment to prior employers
• 5 years of experience in Information Security or Security Engineering.
• One or more industry-recognized certifications (e.g. CISSP SANS/GIAC CCNA equivalent).
• Strong experience securing AWS networking (NACLs Security Groups ALB/NLB Transit Gateway Network Firewall).
• Hands-on experience with NGFWs WAFs load balancers and enterprise network segmentation.
• Strong scripting or automation skills (Python PowerShell or similar).
• Deep understanding of subnetting routing and network isolation principles.
• Experience with SaaS security platforms CASB or SSE tooling.

Preferred Qualifications and Skills

• Familiarity with identity-driven security models (SSO OAuth API tokens service principals).
• Working knowledge of Azure DevOps Terraform or infrastructure-as-code workflows.
• Experience operating in large complex enterprise environments.
• Ability to produce high-quality technical documentation and security standards.
• Strong communication and collaboration skills across technical and non-technical teams.
• Exposure to AI systems model-assisted tooling or developer copilots in an enterprise context.

Whats in it for You

When you join CoStar Group youll 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 Groups Diversity Equity & Inclusion 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.

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CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing