{"id":1427788,"url":"https://alion.io/job/costargroup-sr-security-engineer","title":"Sr. Security Engineer","company":{"id":6056,"name":"CoStar Group","domain":"costargroup.com","url":"https://alion.io/company/costargroup","size_band":"1001-5000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"A","score":85,"open_postings":88,"ghost_share":0,"stale_share":0.591,"repost_share":0,"time_to_fill_p50_days":37,"computed_at":"2026-10-13T05:45:00Z"}},"role":"Security","role_family":"Security","seniority":"senior","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Arlington, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":115000,"max":203000,"currency":"USD","period":"year","gross":null,"usd_annual":203000},"salary_estimate":null,"experience_years_min":5,"visa_sponsorship":true,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AWS","optional":false},{"name":"Least Privilege","optional":false},{"name":"PowerShell","optional":false},{"name":"Python","optional":false},{"name":"Threat Modeling","optional":false},{"name":"Azure","optional":true},{"name":"Azure DevOps","optional":true},{"name":"Terraform","optional":true}],"status":"live","first_seen_at":"2026-06-29T00:00:00Z","employer_posted_date":"2026-06-29","last_verified_at":"2026-10-12T19:36:53Z","board_verified":true,"closed_at":null,"days_open":106,"trust":{"level":"ok","repost_count":0,"flags":[],"days_open":106},"description":"Sr. Security EngineerJob Description\nOverview\nCoStar Group 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.\nWe 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.\nWe are seeking a Senior Security Engineer with experience in Network, SaaS, and AI Security to help evolve and safeguard CoStar’s enterprise security posture across network infrastructure, cloud services, SaaS platforms, and emerging AI systems.\nThis 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.\nThis position can be located in Arlington or Richmond, VA and is in office Monday through Thursday and work from home on Friday.\nResponsibilities\nNetwork & Cloud Security\nProvide engineering expertise to ensure enterprise network changes are designed and implemented securely (on-prem and cloud).\nAudit existing network designs and infrastructure configurations and recommend improvements to security posture.\nEvaluate firewall change requests across on-premise and cloud environments.\nDesign, enforce, and audit policies for Next Generation Firewalls (NGFW), load balancers, routers, switches, and wireless infrastructure.\nManage Secure Service Edge (SSE) platform\nSaaS Security\nPartner with application owners and third-party risk teams to review SaaS security architecture and control effectiveness.\nOperate and tune SaaS security tooling (e.g., CASB/SSE capabilities) to detect risky behavior, misconfigurations, and data exfiltration paths.\nDefine and enforce SaaS security standards for logging, identity integration, and least-privilege access.\nSupport SaaS incident investigation and remediation efforts in coordination with legal, privacy, and compliance teams.\nDevelop reusable SaaS security review patterns and documentation for engineering and procurement teams.\nAI & Emerging Technology Security\nAssess security risks associated with AI platforms, copilots, and agent-based systems, including model access controls, prompt/data leakage risks, and tool/plugin abuse.\nPartner with engineering teams to design security controls for AI-assisted workflows and developer tools.\nContribute to governance models for AI usage, including enforcement of network, identity, and data security boundaries.\nMonitor AI-related telemetry and logs to identify anomalous behavior, data exposure, or misuse patterns.\nSupport threat modeling and risk assessments for AI integrations with enterprise systems and SaaS platforms.\nStay current on AI security threats, abuse patterns, and control frameworks, translating them into actionable enterprise safeguards.\nBasic Qualifications\nBachelor’s Degree is required from an accredited, not for profit, in-person university or college. \nA track record of commitment to prior employers \n5+ years of experience in Information Security or Security Engineering.\nOne or more industry-recognized certifications (e.g., CISSP, SANS/GIAC, CCNA, equivalent).\nStrong experience securing AWS networking (NACLs, Security Groups, ALB/NLB, Transit Gateway, Network Firewall).\nHands-on experience with NGFWs, WAFs, load balancers, and enterprise network segmentation.\nStrong scripting or automation skills (Python, PowerShell, or similar).\nDeep understanding of subnetting, routing, and network isolation principles.\nExperience with SaaS security platforms, CASB, or SSE tooling.\nPreferred Qualifications and Skills\nFamiliarity with identity-driven security models (SSO, OAuth, API tokens, service principals).\nWorking knowledge of Azure DevOps, Terraform, or infrastructure-as-code workflows.\nExperience operating in large, complex enterprise environments.\nAbility to produce high-quality technical documentation and security standards.\nStrong communication and collaboration skills across technical and non-technical teams.\nExposure to AI systems, model-assisted tooling, or developer copilots in an enterprise context.\nWhat’s in it for You\nWhen 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.\nWe offer you generous compensation and performance-based incentives. CoStar Group also invests in your professional and academic growth with internal training, and tuition reimbursement.\nOur benefits package includes (but is not limited to):\nComprehensive healthcare coverage: Medical / Vision / Dental / Prescription Drug\nLife, legal, and supplementary insurance\nVirtual and in person mental health counseling services for individuals and family\nCommuter and parking benefits\n401(K) retirement plan with matching contributions\nEmployee stock purchase plan\nPaid time off\nTuition reimbursement\nOn-site fitness center and/or reimbursed fitness center membership costs (location dependent), with yoga studio, Pelotons, personal training, group exercise classes\nAccess to CoStar Group’s Diversity, Equity, & Inclusion Employee Resource Groups\nComplimentary gourmet coffee, tea, hot chocolate, fresh fruit, and other healthy snacks\nWe 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.\nThe final salary or hourly rate offered for this role will fall within the range set forth below based on a variety of factors, including but not limited to, geographic location, skills, and competencies.\nBase Compensation: $$115,000.00-$203,000.00 Annually\nCoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing","description_format":"text","description_chars":6769,"description_truncated":false,"requirements":{"experience_years_min":5,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[]},"benefits":["Equity","Retirement plans"],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Professional Services","Real Estate","E-learning","Virtual Events"],"lifecycle":[{"event":"open","at":"2026-09-29T00:20:12Z"}],"visa":[],"liveness":{"score":11,"band":"cold","label":"Long shot","p_open":1,"p_active":0.375,"p_room":0.28,"age_days":106,"expected_fill_days":37,"reasons":["conf:10","stale_co","velocity","win:tail","crowd:brand"],"computed_at":"2026-10-13T05:45:00Z"},"pay":{"stated_usd_annual":203000,"is_top_pay":true},"html_url":"https://alion.io/job/costargroup-sr-security-engineer","json_url":"https://alion.io/job/costargroup-sr-security-engineer.json","meta":{"generated_at":"2026-10-13T06:54:56Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":10213,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-14T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":6056},"rest":"https://alion.io/mcp/rest/get_company?id=6056"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fcostargroup-sr-security-engineer"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fcostargroup-sr-security-engineer"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fcostargroup-sr-security-engineer"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/costargroup-sr-security-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fcostargroup-sr-security-engineer"}]}