{"id":3413948,"url":"https://alion.io/job/fis-senior-software-engineer-ledger-store","title":"Senior Software Engineer, Ledger Store","company":{"id":4808,"name":"FIS","domain":"fisglobal.com","url":"https://alion.io/company/fis","size_band":"1001-5000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"B","score":81,"open_postings":74,"ghost_share":0.027,"stale_share":0.649,"repost_share":0.054,"time_to_fill_p50_days":26,"computed_at":"2026-11-03T05:54:40Z"}},"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":["United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":83000,"max_usd":162000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":139},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Model Context Protocol","optional":false},{"name":"Rust","optional":false}],"status":"live","first_seen_at":"2026-10-28T18:44:31Z","employer_posted_date":"2026-10-28","last_verified_at":"2026-11-03T04:38:18Z","board_verified":true,"closed_at":null,"days_open":5,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":5},"description":"Are you curious, motivated, and forward-thinking?\nAt FIS, you’ll work on some of the most complex and impactful challenges in modern banking, helping build next-generation, AI-enabled platforms used by financial institutions worldwide. We foster an environment that values ownership, autonomy, and end-to-end responsibility, where engineers are encouraged to take initiative, make meaningful technical decisions, and ship solutions directly into production. We believe in open, collaborative, and ownership-driven teams with a strong focus on real-world impact.\nAbout the team:\nOpenCoreOS is building an AI-enabled banking platform for Tier-1 financial institutions within FIS. Our foundation is a thin ledger: a fast, reliable system built on open technologies that gives banks the freedom to build and evolve their services. We combine the autonomy and technical depth of a startup with the scale and long-term commitment of FIS. We use AI throughout engineering and operations, with engineers accountable for design, validation, security and production outcomes.\nAbout the Role:\nYou will build, operate and scale Ledger Store, the replicated double-entry ledger that records every money movement on the platform.\nThe engineering challenge is precise: each transfer must apply exactly once, survive crashes and produce consistent state across replicas. These guarantees must hold at low latency and high throughput, across cloud environments and, where customers require it, on-premises deployments.\nWe look for engineers with experience in distributed or durable systems, strong judgement about correctness and performance, and ownership from design through production operation.\nWhat You Will Work On:\nYou will build, operate and scale Ledger Store, the replicated double-entry ledger that records every\nmoney movement on the platform.\nThe engineering challenge is precise: each transfer must apply exactly once, survive crashes and\nproduce consistent state across replicas. These guarantees must hold at low latency and high\nthroughput, across cloud environments and, where customers require it, on-premises deployments.\nWe look for engineers with experience in distributed or durable systems, strong judgement about\ncorrectness and performance, and ownership from design through production operation.\nCore Responsibilities:\nOwn systems through design, implementation, testing, deployment and production operation.\nMake trade-offs between correctness, latency, throughput and operational complexity explicit.\nEstablish observability and alerting that help engineers detect failures and understand their causes.\nTake part in on-call and incident response. Address root causes and prevent related failures.\nDeliver small, traceable changes supported by tests and measured results.\nUse AI-assisted development, MCP servers and agent workflows where they improve engineering or operational outcomes.\nMentor colleagues and write clear design notes, reviews and operational documentation.\nWhat We Look For:\nYou do not need every item below. Depth in a few areas matters more than familiarity with every technology.\nSystems experience: You have built and operated a distributed or durable system in production.\nCorrectness: You can reason about concurrency, consistency, idempotency and failure modes.\nPerformance: You understand how memory management, allocation, copying and concurrency affect runtime behavior. You find bottlenecks by measuring.\nProgramming depth: We are language agnostic for this role; Rust experience is welcome. You can learn the tools the problem requires.\nProduction ownership: You have debugged critical systems and participated in on-call or incident response.\nEngineering judgement: You evaluate alternatives and explain their trade-offs.\nCommunication: You explain complex systems clearly in discussions, design notes and reviews.\nAI-assisted engineering: You use AI thoughtfully and take responsibility for the quality and safety of the result.\nAlso Valuable:\nFinancial ledgers, payments, core banking or banking modernisation.\nLow-latency systems, high-throughput workloads or tail-latency optimisation.\nDeterministic simulation, fuzzing or property-based testing.\nMulti-cloud, hybrid or on-premises deployments.\nCapacity planning, deployment safety and disaster recovery.\nSecurity and compliance in regulated environments.\nHow We Work:\nWe reason from evidence, reproduce failures before fixing them and measure before optimizing. We build safeguards into systems and use tests to challenge our assumptions.\nThe work involves real constraints: network distance between replicas, strict correctness requirements and customer security and platform processes. You will help make these constraints explicit and design systems that operate reliably within them.\nWhy Join Us?\nWork on the system that records money movement at the foundation of banking infrastructure. Join a small, senior team with high autonomy, substantial technical ownership and responsibility for production outcomes.\nPrivacy Statement\nFIS is committed to protecting the privacy and security of all personal information that we process in order to provide services to our clients. For specific information on how FIS protects personal information online, please see the Online Privacy Notice.\nSourcing Model\nRecruitment at FIS works primarily on a direct sourcing model; a relatively small portion of our hiring is through recruitment agencies. FIS does not accept resumes from recruitment agencies which are not on the preferred supplier list and is not responsible for any related fees for resumes submitted to job postings, our employees, or any other part of our company.","description_format":"text","description_chars":5671,"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":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Crypto Wallets","Financial Software & Embedded Finance","Payment Processing & Gateways"],"lifecycle":[{"event":"open","at":"2026-10-28T18:44:31Z"}],"visa":[],"liveness":{"score":63,"band":"ok","label":"Likely open","p_open":1,"p_active":0.632,"p_room":1,"age_days":5,"expected_fill_days":26,"reasons":["conf:1","stale_co","velocity","win:early","comp:brand"],"computed_at":"2026-11-03T05:54:40Z"},"pay":null,"html_url":"https://alion.io/job/fis-senior-software-engineer-ledger-store","json_url":"https://alion.io/job/fis-senior-software-engineer-ledger-store.json","meta":{"generated_at":"2026-11-03T13:48:08Z","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":19173,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-04T00:00:00Z"}},"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":4808},"rest":"https://alion.io/mcp/rest/get_company?id=4808"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Ffis-senior-software-engineer-ledger-store"},{"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%2Ffis-senior-software-engineer-ledger-store"},{"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%2Ffis-senior-software-engineer-ledger-store"},{"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/fis-senior-software-engineer-ledger-store\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Ffis-senior-software-engineer-ledger-store"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3413948}},{"tool":"search_jobs","arguments":{"company":"fisglobal.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3413948},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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