{"id":594352,"url":"https://alion.io/job/janestreet-dev-network-security-engineer","title":"Network Security Engineer","company":{"id":7349,"name":"Jane Street","domain":"janestreet.com","url":"https://alion.io/company/jane-street","size_band":"1001-5000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"B","score":77,"open_postings":173,"ghost_share":0.295,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":177,"computed_at":"2026-10-08T05:49:30Z"}},"role":"Security","role_family":"Security","seniority":"senior","employment_type":null,"work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":88000,"max_usd":163000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":30},"experience_years_min":7,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agile","optional":false},{"name":"BGP","optional":false},{"name":"OSPF","optional":false}],"status":"live","first_seen_at":"2022-06-30T09:34:59Z","employer_posted_date":"2026-09-21","last_verified_at":"2026-10-09T02:09:33Z","board_verified":true,"closed_at":null,"days_open":1561,"trust":{"level":"ghost","repost_count":0,"flags":["stale","company_stale"],"days_open":1560},"description":"About the Position\nWe are looking for an experienced Network Engineer to join our Network Security team to help us to run, scale and continuously improve our network security infrastructure through hands-on operations, design, and implementation. The ideal candidate would have strong networking fundamentals and experience with security appliances such as firewalls and proxy to join our Network Security team.\nJane Street’s numerous distributed systems are built on an agile, reliable, multi-vendor network infrastructure that supports all traffic profiles, from trading to internet connectivity. Supporting such a large multi-function network requires advanced tooling for monitoring and automation. \nStrong communication and interpersonal skills will be needed to collaborate with colleagues across the firm globally. You will find and resolve issues, plan and execute deployments, and improve systems where possible. In this role, we’ll look to leverage your advanced networking skills and security knowledge to: \nWork closely with Network Engineering on design and deployment of security perimeter and adjacent network infrastructure\nEffectively manage and continuously evolve network segmentation, DMZ, and other aspects of network security\nEvaluate and lab test new platforms for our network security infrastructure\nCollaborate with Cybersecurity on detection and mitigation of threats and vulnerabilities on our network\nInterface with application owners and traders to enable business workflows in a secure way\nProactively enhance support by improving network infrastructure observability, scripting, and communicating requirements to our software engineers\nImprove our network security processes and documentation\nA holistic approach to system design is critical for this role. The Networking department prioritizes flexibility, compatibility, and efficiency when crafting solutions, all while seeking ongoing buy-in and feedback from users across the firm. Our firm’s culture prizes intellectual humility, openness, and continuous improvement, which translates directly to the daily work of this team. We’re all partners working towards shared goals and are always looking for the next best idea that will make our work stronger. \nYour strong communication skills and analytical thinking will be invaluable as we support the daily work of our colleagues and keep our systems operating at the highest standard.\nAbout You\n7+ years of experience operating and deploying network infrastructure\nExperience with routing and network protocols (OSPF, BGP, PIM-SM)\nExperience troubleshooting transport protocols (TCP/UDP)\nStrong understanding of firewall hardware architecture, performance metrics, and its functional components\nExperience with firewall configuration and troubleshooting\nUnderstanding of Public Key Infrastructure and related technologies\nUnderstanding of modern encryption techniques\nHigh capacity to learn; we are interested in how you think, not just what you know\nAbility to context switch, while still being able to prioritize and organize your stack \nIdeally experience with overlay networks (EVPN, VxLAN)\nA flexible and reliable team player who enjoys working in a collaborative environment\nProficiency in a programming language is preferred but not required\nFluency in English is required\nIf you're a recruiting agency and want to partner with us, please reach out to ","description_format":"text","description_chars":3429,"description_truncated":false,"requirements":{"experience_years_min":7,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[{"language":"English","level":"Advanced (C1)","optional":false}]},"benefits":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Network Security","Artificial Intelligence","Machine Learning","Financial AI"],"lifecycle":[{"event":"open","at":"2026-09-10T14:59:02Z"}],"visa":[{"country":"GB","licensed_sponsor":true,"evidence":"Licensed UK visa sponsor (Senior or Specialist Worker, Skilled Worker)","filings_12m":null,"filings_prev_12m":null,"green_card_filings_12m":null,"median_offered_wage_usd":null,"route":"Global Business Mobility: Senior or Specialist Worker; Skilled Worker","cap_exempt":false,"checked_at":"2026-10-08T06:20:15+00:00","sources":["UK Home Office: register of licensed sponsors (workers)"],"filings_for_role_12m":0}],"liveness":{"score":6,"band":"cold","label":"Long shot","p_open":1,"p_active":0.227,"p_room":0.28,"age_days":1560,"expected_fill_days":177,"reasons":["conf:0","velocity","ghost","win:tail","crowd:brand"],"computed_at":"2026-10-08T05:49:30Z"},"pay":null,"html_url":"https://alion.io/job/janestreet-dev-network-security-engineer","json_url":"https://alion.io/job/janestreet-dev-network-security-engineer.json","meta":{"generated_at":"2026-10-09T04:17:45Z","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","counted_by":"address","units_charged":1,"used_today":3855,"day_limit":5000,"remaining_today":1145,"minute_limit":60,"resets_at":"2026-10-10T00:00:00Z"}},"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":7349},"rest":"https://alion.io/mcp/rest/get_company?id=7349"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fjanestreet-dev-network-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%2Fjanestreet-dev-network-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%2Fjanestreet-dev-network-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/janestreet-dev-network-security-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fjanestreet-dev-network-security-engineer"}]}