Senior Full Stack Engineer – Vialto Rewards - London

Salary: £65,000 - 105,000 per year

Requirements:

• 5+ years of professional software development experience building enterprise web applications and services, ideally in payroll, compensation, equity, HR, finance, or tax domains.
• Strong experience designing and building large JavaScript applications with Next.js and/or React, including TypeScript, state management, and performance optimization.
• Strong backend development experience in C# and .NET, including ASP.NET, WebAPI, MVC, and API design for high-integrity calculation and data-processing systems.
• Proven experience with Microsoft Azure, including designing and building cloud solutions using PaaS services, frameworks, and operational tooling.
• Experience delivering systems in regulated or compliance-oriented environments, including security controls, auditability, privacy, and sensitive financial or personal data handling.
• Strong engineering fundamentals, including design patterns, separation of concerns, scalable architecture, and pragmatic trade-offs, with attention to accuracy and reconciliation in calculation-heavy systems.
• Experience with agentic or AI-assisted development workflows such as spec-driven development or agent-driven development using tools like Claude Code or Codex.
• Demonstrated ability to build products that incorporate AI capabilities, including prompt design, LLM API integration, or AI-augmented user experiences.
• Bachelors degree in computer science, Engineering, or a related field required.
• Masters degree preferred.

Responsibilities:

• Build and evolve modern web experiences for Compensation Collection, Shadow Payroll, and Equity products using Next.js, React, and TypeScript.
• Design and implement backend services and APIs using C#, .NET, and WebAPI to support compensation data ingestion, cross-border payroll calculations, equity event processing, and integrations with client systems.
• Deliver Azure-native implementations of shadow payroll calculation engines, compensation aggregation pipelines, and equity tax event workflows.
• Contribute to system architecture and technical design for multi-country payroll, compensation, and equity domains.
• Own production readiness, including logging, monitoring and alerting, reconciliation tooling, incident response support, and operational documentation.
• Apply secure development practices for handling sensitive compensation, payroll, and equity data.
• Partner with product, mobility tax, payroll, and equity subject-matter experts to translate complex regulatory and client requirements into technical plans and deliverables.
• Use agentic development practices with AI coding agents to accelerate design, implementation, testing, and operations across the SDLC.
• Work in a spec-driven development workflow, authoring detailed specifications that guide both human and AI agent implementation.
• Design and implement AI-powered features, including intelligent data extraction, anomaly detection, LLM-assisted user workflows, and retrieval-augmented generation (RAG).
• Evaluate, integrate, and operationalize AI APIs, models, and toolchains within application architectures.
• Mentor and support other engineers through code reviews, pairing, and technical guidance on payroll, compensation, and equity domain patterns.

Technologies:

• AI
• API
• ASP.NET
• Azure
• Backend
• C#
• Claude Code
• Cloud
• Support
• JavaScript
• LLM
• MVC
• PaaS
• RAG
• React
• Security
• TypeScript
• Web
• Android
• CI/CD
• CSS
• Frontend
• Git
• Jest
• Mocha
• Mobile
• NHibernate
• REST
• SAP
• SQL
• TDD
• iOS
• Fullstack

More:

We are Vialto, a market leader in global mobility services and the only stand-alone global mobility business, with a purpose to connect the world. Our global team has over 8,000 staff and we support clients across industries and geographies with cross-border compliance and risk assessment for tax, immigration, business travel, rewards and compensation, and remote work. In this Senior Full Stack Engineer role, you will help build and scale the technology behind Compensation Collection, Shadow Payroll, and Equity, working in a highly regulated, multi-jurisdictional environment on Microsoft Azure while also advancing AI-augmented engineering practices. We offer the chance to work in a dynamic, inclusive culture where colleagues can grow through global opportunities and make an impact across the communities we serve.

last updated 36 week of 2026