Senior Security Engineer

Senior Security Engineer

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Job Description

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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 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.   

We are expanding our enterprise Data Loss Prevention (DLP) program to accelerate impact. The program is live and producing results with Microsoft Purview, but we need more dedicated engineers. We are hiring a Senior DLP Engineer to design, scale, and operationalize Microsoft Purview-based protections across endpoints and Microsoft 365 workloads—partnering with Security Operations, Governance, Risk & Compliance (GRC), Legal/Privacy, and the business.

As the Senior DLP Engineer, you will own the technical strategy, architecture, deployment, and ongoing operations of Microsoft Purview. You will build sustainable detection and prevention capabilities for data exfiltration and misuse, integrate DLP with enterprise workflows (incident response, exception management, change control), and provide clear metrics and executive reporting.

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

Responsibilities

• Own the enterprise DLP architecture and roadmap using Microsoft Purview across Exchange Online, SharePoint Online, OneDrive, Teams, Power BI, and Endpoint DLP on managed devices.

• Design and implement data classification and labeling at scale (sensitivity labels, automatic/manual labeling, protection actions) aligned to the organization’s data taxonomy.

• Build, test, and tune DLP policies for high‑risk exfiltration vectors (email, cloud storage, chat, web uploads, endpoints: removable media, print, clipboard, Bluetooth, RDP, browser downloads).

• Stand up and mature advanced classifiers and detections (Sensitive Information Types, Exact Data Match schemas, trainable classifiers) with continuous improvement cycles.

• Integrate DLP with incident management and SOC workflows (alert triage, case management, evidence capture, automation) and with SIEM (e.g., Microsoft Sentinel) using KQL analytics.

• Partner with Identity, Endpoint, and Collaboration teams to enforce device/user trust prerequisites, and with Compliance/Legal on retention, eDiscovery, and privacy-by-design.

• Create enablement content: policy tips, just‑in‑time guidance, and training for end users and privileged administrators to reduce friction and false positives.

• Establish exception and change management processes, including time‑bound exceptions with compensating controls and periodic recertification.

• Publish dashboards and KPIs to leadership (coverage, alert volumes, true‑positive rates, MTTR, prevented exfiltration, policy drift).

• Mentor junior engineers and act as the primary subject‑matter expert for Microsoft Purview DLP.

Basic Qualifications

• Bachelor’s Degree required from an accredited, not for profit university or college.  

• A track record of commitment to prior employers 

• 6+ years in information security with 3–5+ years focused on enterprise DLP.

• Hands‑on expertise deploying and operating Microsoft Purview Information Protection & DLP at 5k+ user scale, including Endpoint DLP and M365 workloads.

• Practical experience with sensitivity labels, automatic and manual labeling, Sensitive Information Types, Exact Data Match (EDM), and trainable classifiers.

• Proficiency with Kusto Query Language (KQL), PowerShell, and API/automation for policy management and reporting.

• Experience integrating DLP with SIEM/SOAR, SOC runbooks, and incident/alert handling processes.

• Strong stakeholder skill