{"id":141418,"url":"https://alion.io/job/shieldpay-senior-software-engineer","title":"Senior Software Engineer","company":{"id":51412,"name":"Shieldpay","domain":"shieldpay.com","url":"https://alion.io/company/shieldpay","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Teamtailor","truth_index":null},"role":"Backend","role_family":"Backend","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":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":84000,"max_usd":160000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":125},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"ASP.NET Core","optional":false},{"name":"C#","optional":false},{"name":"Dependency Injection","optional":false},{"name":"Entity Framework Core","optional":false},{"name":"ETL/ELT","optional":false},{"name":"JavaScript","optional":false},{"name":"JQuery","optional":false},{"name":"SQL","optional":false},{"name":"TypeScript","optional":false},{"name":"AWS","optional":true},{"name":"AWS Lambda","optional":true}],"status":"live","first_seen_at":"2026-07-28T14:47:47Z","employer_posted_date":"2026-07-28","last_verified_at":"2026-10-18T09:23:44Z","board_verified":true,"closed_at":null,"days_open":81,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":81},"description":"Impact and Responsibilities\nWe are seeking a Senior Software Engineer who thrives on untangling complex systems and modernising core infrastructure without breaking production. This is an exciting opportunity to modernise core C#/SQL systems! Extract legacy business logic, build clean services, and verify changes in shadow mode with zero downtime to revenue flows.\nExtract business rules scattered across C#, embedded JavaScript and undocumented SQL stored procedures into a clean, tested, dependency-free rules assemblies.\n\nBuild new services cleanly. with proper Dependency Injection (DI), robust authentication / authorization, structured logging, and full observability.\n\nWork fluently across both legacy .NET Framework 4.8 (ASP.NET MVC5, WebAPI 2, EF6) and modern .NET, as both will coexist for the whole transition period.\n\nNavigate across the multiple existing systems such as the API façade, the ETL pipeline, the SNS/SQS event bus, since neither system is self-sufficient and most real bugs live in the coupling, not one side.\n\nDeploy changes using shadow-mode verification (compute, log, and compare against legacy outcomes without writing) until equivalence is rigorously proven.\n\nRefactor and optimise heavy SQL Server stored procedures and backend logic with total precision ensuring client-money correctness is never compromised.\n\nWhat we're looking for in you\nSenior-level, hands-on experience in modern .NET (.NET 6+) paired with deep, comfortable familiarity with legacy .NET Framework 4.8 (ASP.NET MVC 5, WebAPI 2, Entity Framework 6). We need someone who respects the legacy code and is happy working in it today.\n\nHigh proficiency in reading, understanding, and safely refactoring complex, stored-procedure-heavy database logic.\n\nWorking proficiency in JavaScript/TypeScript. You’ll be interacting with both jQuery on the legacy .NET front end and modern TypeScript microservices on our sister platform.\n\nA strong \"legacy technology\" instinct over a \"rewrite everything\" approach. You favour stability, predictability, and incremental progress over shiny trends.\n\nExperience or comfort with golden-master testing, diffing, and shadow verification to mathematically/logically prove equivalence to legacy outputs.\n\nThe ability to hold two disparate architectures in your head at once and reason through their edge cases, data flows, and coupling points.\n\nNice-to-Haves\nHands-on experience with AWS Lambda, SQS, SNS, and RDS.\n\nComfort operating alongside an in-house AI-agent orchestrator that supports and automates parts of our SDLC.\n\nOur Promise: Shieldpay is an equal opportunities employer. For Shieldpay building a fair and transparent workforce begins with the recruitment process that does not discriminate on the grounds of gender, sexual orientation, pregnancy or maternity, gender reassignment, race, colour, nationality, ethnic or national origin, religion or belief, disability or age. We offer flexible working options, such as flexible hours and hybrid work, to support our employees' work-life balance","description_format":"text","description_chars":3036,"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":["Flexible schedule","Hybrid work"],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Payment Processing & Gateways"],"lifecycle":[{"event":"open","at":"2026-07-28T14:47:47Z"}],"visa":[{"country":"GB","licensed_sponsor":true,"evidence":"Licensed UK visa sponsor (Skilled Worker)","filings_12m":null,"filings_prev_12m":null,"green_card_filings_12m":null,"median_offered_wage_usd":null,"route":"Skilled Worker","cap_exempt":false,"checked_at":"2026-10-17T06:21:15+00:00","sources":["UK Home Office: register of licensed sponsors (workers)"],"filings_for_role_12m":0}],"liveness":{"score":13,"band":"cold","label":"Long shot","p_open":1,"p_active":0.45,"p_room":0.28,"age_days":80,"expected_fill_days":26,"reasons":["conf:0","win:tail","crowd:"],"computed_at":"2026-10-17T05:46:00Z"},"pay":null,"html_url":"https://alion.io/job/shieldpay-senior-software-engineer","json_url":"https://alion.io/job/shieldpay-senior-software-engineer.json","meta":{"generated_at":"2026-10-18T12:26:56Z","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":18384,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-19T00:00:00Z"}},"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":51412},"rest":"https://alion.io/mcp/rest/get_company?id=51412"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fshieldpay-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%2Fshieldpay-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%2Fshieldpay-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/shieldpay-senior-software-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fshieldpay-senior-software-engineer"}]}