{"id":1232679,"url":"https://alion.io/job/xtxmarkets-security-engineer","title":"Security Engineer","company":{"id":1868233,"name":"XTX Markets","domain":"xtxmarkets.com","url":"https://alion.io/company/xtxmarkets","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":null},"role":"Security","role_family":"Security","seniority":"junior","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":43000,"max_usd":121000,"period":"year","method":"global_role_cell_scaled_by_country","sample_n":309},"experience_years_min":1,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Go","optional":false},{"name":"Machine Learning","optional":false},{"name":"Python","optional":false}],"status":"live","first_seen_at":"2026-08-13T12:36:56Z","employer_posted_date":"2026-08-13","last_verified_at":"2026-09-29T20:31:11Z","board_verified":true,"closed_at":null,"days_open":48,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":48},"description":"The Firm\nXTX Markets is a leading algorithmic trading firm which uses state-of-the-art machine learning technology to produce price forecasts for over 53,000 financial instruments across equities, fixed income, currencies, commodities and crypto. It uses those forecasts to trade on exchanges and alternative trading venues, and to offer differentiated liquidity directly to clients worldwide. The firm trades over $250bn a day across 35 countries and has over 300 employees based in London, Singapore, New York, Paris, Bristol, Mumbai, Yerevan and Kajaani.\nWe leverage the talent of the people who work here, modern computational techniques and state-of-the-art research infrastructure to analyse large data sets across markets quickly and efficiently, to maximize the effectiveness of our proprietary trading algorithms. We are actively seeking new methods and ideas. The models that drive our trading strategies have evolved considerably over the last 10 years, from econometric methods that gave our company its name, to trees, to neural networks, to modern deep learning architectures.\nXTX Markets has an unrivalled level of computational resources in the trading industry, with a growing research cluster currently containing well over 25,000 GPUs with more than 1 exabyte of usable storage. Teams across the firm include world-class researchers, developers and technologists with backgrounds in pure math, programming, physics, computer science and machine learning. The firm is also constructing a large-scale data centre in Finland to future-proof its significant computational capabilities.\nAt XTX Markets technology is our business and we are a diverse organization which attracts outstanding talent from across all industry backgrounds. We are focused on teamwork and our people collaborate on all aspects of the business, working openly and with respect for each other, our clients and the market. Our culture is non-hierarchical and one where everyone is valued. We strive for excellence in everything we do.\nThe Role\nThe Information Security team at XTX Markets is accountable for all aspects of the firm’s IT security. From obtaining and transforming events and signals into actionable intelligence, to helping design and implement authentication and authorisation systems, and other security tools that underpin the XTX environment.\nThe team also assess third party security, as well as working diligently to keep XTX in compliance with a range of world-wide regulatory information security requirements. \nOur Security team works to create and maintain the safest operating environment for XTX Markets users and developers. In this role, you will work with software engineers to proactively identify security flaws and engineer technical solutions to a defensive mindset. \nThis is a hands-on role. XTX prides itself on its ability to create and maintain software and systems that precisely meet our needs.\nWe handle information at large scale and across multiple locations, so we need to anticipate and protect against attackers. You will work closely with teams to improve our detection capabilities, and to design defence-in-depth controls that limit attackers' ability to move inside our network.\n\nResponsibilities \n\nAt XTX, security engineers are engaged in requirements gathering, architecting, prototyping, and developing both internal tools and broader infrastructure in conjunction with partner teams around XTX.\nThe successful candidate will be expected to work across a broad range of security roles and projects, including compliance related tasks.\n\nEssential Attributes\n\nApproximately one to three years’ experience in Information Security.\nProficiency in at least one statically typed language; development at XTX is primarily in Golang, though previous experience in Go is not a pre-requisite. Scripting is mainly in Python.\nKnowledge of how systems are built as well as how to break them.\nStrong communication and interpersonal skills.\nAble to write clearly and succinctly.\nRapid learner with strong attention to detail.\nAble to work autonomously and prioritise as required.\nWilling to admit mistakes and seek feedback to improve performance.\n\n Desirable Attributes\nPersonal projects which you can show or talk about.\nExperience playing CTFs.\nSecurity certifications demonstrating practical ability, e.g. OSCP.\n\nBenefits\nOnsite gym, sauna, and fitness classes at no charge (Wellbeing Space).\nExtensive medical benefits including an on-site doctor and therapist at no charge.\nBreakfast and lunch provided daily.\nVarious supports for caregivers, including emergency dependent care.\nBeautiful King’s Cross office: (Office Tour).\n25 days paid holiday per year + statutory holiday and paid sick days.\nGenerous Pension contributions.\nWe work 4 days per week in the office, 1 from home unless stated otherwise.","description_format":"text","description_chars":4835,"description_truncated":false,"requirements":{"experience_years_min":1,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":[],"lifecycle":[{"event":"open","at":"2026-09-25T15:25:19Z"}],"liveness":{"score":20,"band":"cold","label":"Long shot","p_open":1,"p_active":0.548,"p_room":0.36,"age_days":47,"expected_fill_days":30,"reasons":["conf:9","urgency","win:tail","crowd:junior"],"computed_at":"2026-09-30T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/xtxmarkets-security-engineer","json_url":"https://alion.io/job/xtxmarkets-security-engineer.json","meta":{"generated_at":"2026-09-30T20:05:46Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","usage":{"tier":"search","counted_by":"address","units_charged":0,"used_today":0,"day_limit":null,"remaining_today":null,"minute_limit":null,"resets_at":"2026-10-01T00:00:00Z"}}}