Principal Engineer

Pluxee is a global player in Employee Benefits and Engagement that operates in 28 countries. Pluxee helps companies attract, engage, and retain talent thanks to a broad range of solutions across Meal & Food, Well-‏being, Lifestyle, Reward & Recognition, and Public Benefits. Powered by leading technology and more than 5,600 engaged team members, Pluxee acts as a trusted partner within a highly interconnected B2B2C ecosystem made up of more than 500,000 clients, 37 million+ consumers and 1.7 million+ merchants. Conducting business for more than 45 years, Pluxee is committed to creating a positive impact on local communities, supporting well-‏being at work for employees, and protecting the planet. YOUR NEXT CHALLENGE Deliver scalable, secure, resilient and cost-effective end-to-end technical solutions that meet product, business, functional and non-functional requirements. Provide visible technical leadership that improves engineering quality, delivery confidence, team capability and consistency across squads. Align product technology roadmaps with business strategy, Pluxee enterprise standards, security requirements and global platform direction. Ensure architecture decisions, system documentation and operational controls are current, traceable and suitable for governance and audit. Technical leadership for products and platforms Own and evolve the end-to-end technical architecture for .NET digital products and shared platform capabilities. Act as the senior technical authority for product squads, resolving complex design decisions and providing clear, pragmatic technical direction. Remain hands-on through prototypes, reference implementations, code reviews, troubleshooting and targeted delivery of high-risk or high-value components. Partner with Product Owners, Product Managers and Digital Asset Owners to translate product outcomes into coherent technical capabilities, features and user stories. Identify technical risks, dependencies and constraints early, with proportionate mitigation and decision recordsEngineering excellence and software quality Establish and promote engineering standards covering clean architecture, SOLID principles, secure coding, automated testing, code quality and maintainability. Define guardrails for APIs, event-driven integration, data access, error handling, logging, monitoring and operational readiness. Champion performance engineering, resilience testing, accessibility by design and production supportability. Coach engineers and technical lead through design reviews, pairing, code reviews and communities of practiceLead root-cause analysis for complex technical issues and ensure systemic improvements are captured in product backlogs. Architecture governance and documentation Maintain an accurate architecture repository and system inventory covering applications, integrations, infrastructure, data flows, technology standards and lifecycle status.Produce and maintain solution context, container, component, deployment, sequence, integration and data-flow views at an appropriate level of detail. Document significant decisions using architecture decision records and ensure designs remain traceable to product and non-functional requirements. Lead solution design reviews and assure country-specific solutions against Pluxee global enterprise architecture and security standards. Modernisation, cloud and DevOps Shape modernisation roadmaps for legacy .NET applications, including incremental decomposition, API enablement, cloud adoption and technical debt retirement. Guide the appropriate use of Azure services, containers, application services, messaging, API management, relational and NoSQL data platforms. Improve continuous integration, continuous delivery, automated quality controls, infrastructure management, observability and release safety. Promote cost-effective architecture and operational practices, including capacity planning, service ownership and FinOps awareness. Lead the adoption of reusable global components and shared platforms where they meet UK product and regulatory needs Security, compliance and operational integrity Ensure threat modelling, secure design, privacy by design, vulnerability management and data protection controls are integrated into engineering ways of working. Work with security, risk, architecture and operations stakeholders to address audit findings and maintain evidence of appropriate controls. Define non-functional requirements and acceptance criteria for availability, recoverability, performance, security, accessibility and support. Ensure technical designs include suitable monitoring, alerting, backup, disaster recovery and incident response considerations. YOU ARE A MATCH IF... Education: A degree in Computer Science, Software Engineering or related discipline, or equivalent professional experience. Relevant Microsoft Azure or architecture certifications are advantageous. Work Experience: Extensive experience designing, building and operating enterprise-grade .NET products, with demonstrable technical leadership across multiple delivery teams or complex platforms. Deep practical knowledge of C#, modern .NET, ASP.NET Core, RESTful APIs, distributed systems, asynchronous messaging and SQL-based data platforms. Experience modernising legacy .NET Framework applications, including MVC, Entity Framework, T-SQL, stored procedures, Web API, SOAP and WCF integrations. Strong knowledge of software architecture and design patterns, domain-driven design, modular architecture, microservices trade-offs, integration patterns and API lifecycle management. Hands-on experience with Azure services such as App Service, Functions, Service Bus or queues, API Management, Azure SQL, Cosmos DB, containers and monitoring services. Strong understanding of CI/CD, automated testing, code quality controls, observability, incident diagnosis, reliability engineering and DevSecOps practices. Knowledge of application security, identity and access management, OWASP guidance, threat modelling, privacy by design and relevant compliance requirements. Experience producing high-quality architecture artefacts, including context and container views, integration diagrams, data-flow diagrams, deployment views, technology roadmaps and architecture decision records. Ability to communicate complex technical issues clearly to engineers, product stakeholders, senior leaders, auditors and suppliers. Desirable technical skills: Experience in payments, prepaid cards, employee benefits, rewards, vouchers, cashback or regulated financial services. Experience with frontend or cross-platform technologies such as Blazor, modern JavaScript frameworks or .NET MAUI. Experience operating in a multi-country enterprise and integrating global platforms with country-specific products. Understanding FinOps, cloud cost optimisation, accessibility standards and software supply-chain security. Languages: Fluent English; French is advantageous Location Hybrid - Milton Keynes office. ☀️ Happy at work 1) A meaningful job: Be the change! Help us build the future of employee benefits by bringing to life sustainable and personalized experiences and contribute to make a real impact on millions of lives. Our business model delivers not just for individuals but their communities too, by supporting local businesses and economies. 2) A great culture: People matter - a lot! Be part of a multicultural team that moves as one in a fast paced and innovative environment. We respect and care authentically about our people, we embrace well-being and work-life balance, new ideas and we have a lot of fun! 3) An empowering environment: Be yourself! At Pluxee we proudly embrace diversity and value the uniqueness of our talents, fostering an inclusive workplace where all abilities are celebrated, and equal learning and growing opportunities are a given.