Senior Zero Trust Network Access; ZTNA) Engineer- Arlington, VA

Job Description

Overview Co Star  Group (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.

This Senior Zero Trust Network Access (ZTNA) Engineer role will augment CoStar’s zero-trust engineering teams, providing expertise in the architecture, implementation, operation, and continuous improvement of the company’s cloud-delivered ZTNA and Security Service Edge (SSE) platforms. This role will directly support CoStar’s global population of 9,000+ employees by helping to provide secure, reliable, and high‑performing access to enterprise resources.

Our team is seeking a Senior Zero Trust Network Access Engineer who combines deep expertise in modern secure access technologies with advanced network troubleshooting skills. This is not solely a ZTNA platform administration role. The successful candidate must understand end‑to‑end network behavior and independently diagnose complex connectivity, authentication, routing, DNS, performance, and application‑access issues across endpoints, enterprise networks, cloud security platforms, identity providers, and applications.

This engineer will be a hands‑on technical leader who owns critical services from design through production operations, leads difficult troubleshooting efforts, and drives solutions that help the company scale.

This position is in Arlington, VA and offers a schedule of Monday through Thursday in office, with the option to work from home on Friday.

• Design, deploy, configure, operate, and optimize enterprise Zero Trust Network Access (ZTNA) and Security Service Edge (SSE) platforms, such as Zscaler, Netskope, Cloudflare, Palo Alto Prisma Access, or Cisco Secure Access.
• Design and manage ZTNA security and access policies, including traffic steering, application segmentation, policy evaluation, access controls, and performance optimization.
• Lead migrations from traditional VPN, on‑premises security architectures, and other ZTNA or SaaS solutions to modern cloud-delivered ZTNA platforms while maintaining secure and reliable access.
• Serve as a senior technical escalation point for complex connectivity, authentication, routing, application‑access, and performance issues.
• Lead cross‑domain troubleshooting across endpoints, DNS, routing, NAT, proxies, firewalls, identity providers, ZTNA and SSE services, cloud networks, and enterprise applications.
• Perform packet‑level and session‑level analysis using tools such as Wireshark, TCPDump, platform logs, flow records, endpoint telemetry, and digital experience monitoring data.
• Diagnose TCP/IP, DNS, DHCP, TLS, MTU and MSS, fragmentation, asymmetric routing, proxy, firewall‑session, tunnel, and application‑performance issues across end‑to‑end traffic paths.
• Troubleshoot advanced ZTNA and SSE…