{"id":3044421,"url":"https://alion.io/job/ig-senior-software-engineer","title":"Senior Software Engineer","company":{"id":38407,"name":"IG","domain":"ig.com","url":"https://alion.io/company/ig","size_band":"5000+","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","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":173000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":130},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Apache Kafka","optional":false},{"name":"AWS","optional":false},{"name":"Azure","optional":false},{"name":"C++","optional":false},{"name":"CI/CD","optional":false},{"name":"Clojure","optional":false},{"name":"GCP","optional":false},{"name":"Java","optional":false},{"name":"Kotlin","optional":false},{"name":"Kubernetes","optional":false},{"name":"LLM Guardrails","optional":false},{"name":"Python","optional":false},{"name":"Rust","optional":false},{"name":"Scala","optional":false},{"name":"SQL","optional":false}],"status":"live","first_seen_at":"2026-10-21T23:52:47Z","employer_posted_date":"2026-10-21","last_verified_at":"2026-10-22T03:49:57Z","board_verified":true,"closed_at":null,"days_open":1,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":1},"description":"Job Title\nSenior Software EngineerJob Description\nSenior Software Engineer - Java\nOrder Management System (OMS) - Trading Platform\nSo, who are we?\nIG Group is a FTSE 100 fintech operating across five continents, serving over 1.4m customers and handling billions of dollars in transactions - built on scale, trust, and proof. We didn't pivot to innovation; it's how we've always operated. What that means for the people who work here is real: genuinely complex problems to solve, the technology and resources to tackle them properly, and the kind of scope that's rare in established businesses.\nThe bar is high - bring a curious and forward-thinking mindset and we'll give you the platform to define what comes next.\nJoin us at IG - the future gets built here.\nThe Team:\nWe are a small, cross-functional team that owns its services end to end, in production. We work closely with product and the business - close enough that “what should this order do next?” is a conversation, not a ticket.\nMuch of the interesting work lives at the OMS boundary. Because the order flow runs through this service, the OMS describes the business process directly - and that is exactly what makes the role a demanding one, and an unusually influential one.\nYour role in the team’s success:\nThis team owns the Order Management System (OMS), a central part of our trading platform. The OMS controls the order flow for incoming orders: it is where an order’s path through the platform is decided, tracked and recorded.\nYou will join as a senior engineer on that service: designing and building Java services where correctness is not negotiable and latency is measured rather than guessed. When something goes wrong here, the teams who trade and support our clients feel it straight away.\nWe are looking for an engineer who wants the domain as much as the engineering. You do not need to arrive as a trading expert, but you do need to want to become one.\nWhat you’ll do:\nTake ownership of work from elaboration through to delivery and support: shaping requirements with stakeholders, designing the solution, building it, testing it, shipping it and running it.\nDesign and build low-latency, high-throughput Java services that accept, route and manage orders across the full order lifecycle.\nBuild and maintain market connectivity: FIX sessions and venue-specific protocols, including certification and conformance testing with counterparties.\nModel and evolve order and execution state: order types, time-in-force, partial fills, amends, cancels, rejects, drop copies, reconciliation and end-of-day processing.\nTreat correctness as a first-class concern: idempotency, ordering guarantees, deterministic replay, and a complete, auditable trail of every order state transition.\nSupport the platform in production during market hours, including participation in the team’s on-call rotation and incident response.\nRaise the bar around you: design and code review, pairing, mentoring, and steady improvement of the team’s testing, tooling and observability.\nTranslate between trading language and system behaviour - in both directions - when working with traders, dealers, quants and business stakeholders.\nBuilding software with AI:\nAI-assisted development is part of how this team works, not an experiment running alongside it. We expect engineers to be fluent with the tooling and equally clear about its limits.\nUse AI coding assistants as part of your everyday toolkit - scaffolding, refactoring, test generation, and finding your way around unfamiliar code.\nApply the same rigour to AI-generated code as to human-written code. You remain accountable for everything that reaches production; in a trading system that accountability is absolute.\nKnow when the assistant helps and when it gets in the way and be able to explain and defend every design decision you ship regardless of how the first draft was produced.\nHelp the team build good practice: prompting and context patterns, project rules and guardrails, evaluating output, and reviewing critically.\nContribute to developer experience and automation more broadly - AI-assisted testing, documentation, migrations and support tooling.\nWhat you’ll need:\nEssential\nStrong commercial experience building and running production backend systems in Java. This is a Java role on a Java platform; comfort with a recent LTS release (17 / 21 or later) and modern language features is expected.\nReal depth on the JVM: concurrency and the memory model, collections, allocation and garbage collection behaviour, and the ability to profile and measure latency and throughput rather than reason about them by feel.\nDistributed systems fundamentals - messaging, delivery semantics, idempotency, ordering, backpressure, partial failure and recovery - and sound judgement about which guarantees a given problem actually requires.\nTesting you would stake a release on: unit, integration and end-to-end, with an appetite for deterministic or property-based approaches where the domain warrants them.\nSolid SQL and relational data modelling, including schema evolution in a system that cannot lose or misstate an order.\nComfort with CI/CD, containers, infrastructure as code, and operating what you build: metrics, tracing, structured logging, alerting.\nClear communication with technical and non-technical audiences alike - you can run a design discussion with dealers in the room.\nOwnership: you take a problem from a vague requirement to monitored, documented, running software.\nStrongly preferred - trading domain experience here is what distinguishes a strong candidate for this role from a strong general backend engineer.\nHands-on experience with an OMS, EMS, PMS or comparable trading system, buy-side or sell-side.\nFIX protocol in production: FIX 4.2 / 4.4 / 5.0 (FIXT), the distinction between session and application layers, custom tags and counterparty dialects, QuickFIX/J or an equivalent (including in-house) engine, and certification with venues, brokers or liquidity providers.\nOther market connectivity: native or binary exchange APIs (ITCH / OUCH and similar), broker and LP APIs, market data feeds, direct market access and order routing.\nTrading domain knowledge: the order lifecycle end to end, order types and time-in-force, execution algorithms, allocations, clearing and settlement, corporate actions, margin and risk, and multi-asset instrument and reference data - equities, futures, options, FX, CFDs.\nRegulatory context and why it shapes design: MiFID II and best execution, transaction and trade reporting, audit trails, surveillance touchpoints.\nStrongly preferred - engineering\nEvent sourcing and CQRS - having designed, built or run a system along these lines is a real advantage in a service where every state transition matters.\nOther JVM languages - Kotlin, Scala, Clojure - as evidence that you know the platform beyond a single language.\nLow-latency techniques and tooling: lock-free data structures, off-heap or allocation-free design, and libraries such as Aeron, Chronicle or the LMAX Disruptor.\nEvent streaming (Kafka or similar), Kubernetes, and public cloud (AWS / GCP / Azure).\nWelcome, but not required\nExperience with Python, or with lower-level languages such as C++ or Rust, is an advantage - particularly if you have used them in a trading environment. To be unambiguous, though: the language you will write day to day is Java, and we are not asking you to bring another one.\nThe Perks:\nCompetitive salary\nFlexible Benefits Package on top of your salary (12%)\nPrivate medical cover for you and your family\nLife insurance\nContribution to gym memberships\n25 Days holiday, with 1 additional day off to celebrate your Birthday & 2 additional days off a year for voluntary work (28 in total)\nThe option to buy or sell holiday days\nA comprehensive global and local onboarding process\nEnhanced primary (maternity), secondary (paternity), and shared parental pay and leave, as well as a range of support and benefits for parents\nNumber of openings\n1","description_format":"text","description_chars":8002,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Gym membership","Life insurance"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Online Brokerage & Trading Platforms","Forex & CFD Brokers"],"lifecycle":[{"event":"open","at":"2026-10-21T23:52:47Z"}],"visa":[],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":1,"expected_fill_days":14,"reasons":["conf:26","velocity","win:early"],"computed_at":"2026-10-23T05:54:15Z"},"pay":null,"html_url":"https://alion.io/job/ig-senior-software-engineer","json_url":"https://alion.io/job/ig-senior-software-engineer.json","meta":{"generated_at":"2026-10-23T20:32:45Z","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_verified","counted_by":"address","units_charged":1,"used_today":2200,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-24T00:00:00Z"}},"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":38407},"rest":"https://alion.io/mcp/rest/get_company?id=38407"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fig-senior-software-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%2Fig-senior-software-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%2Fig-senior-software-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/ig-senior-software-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fig-senior-software-engineer"}]}