Senior .NET Platform Architect & Tech Leader

PLUXEE UK LTD; Milton Keynes; Hybrid; GBP 110,000 - 135,000; Full time

Job summary

Pluxee seeks a Principal Engineer to provide technical leadership across .NET products and platforms in a hybrid role based in Milton Keynes. You will own end-to-end technical direction, shape architecture, drive governance, and lead cross-team collaboration to deliver secure, scalable software solutions for Payments, Discounts, Benefits and more.

You will stay hands-on with prototypes and reviews, mentor engineers, and ensure the alignment of architecture with business strategy and global

Qualifications

• Extensive experience designing, building and operating enterprise-grade .NET products.
• Strong knowledge of software architecture, patterns and microservices trade-offs.
• Hands-on experience with Azure services and cloud-native patterns.
• Experience modernising legacy .NET applications and integrating APIs.

Responsibilities

• Deliver scalable, secure, resilient and cost-efficient end-to-end technical solutions.
• Provide visible technical leadership that improves engineering quality and delivery confidence.
• Align product technology roadmaps with business strategy and security standards.
• Ensure architecture decisions and documentation are current for governance and audits.
• Act as senior technical authority for product squads and guide complex design decisions.
• Remain hands-on through prototypes, code reviews and targeted delivery of high-value components.
• Partner with Product Owners to translate product outcomes into technical capabilities and user stories.
• Identify risks early with mitigation and clear decision records.
• Establish engineering standards for architecture, testing, observability and security.
• Define guardrails for APIs, data access, monitoring and operational readiness.
• Champion performance engineering and accessibility by design.
• Coach engineers through reviews and communities of practice.
• Lead root-cause analysis and drive systemic improvements into backlogs.
• Maintain architecture repository and lifecycle documentation.
• Lead solution design reviews ensuring alignment with global standards.
• Shape modernisation roadmaps and cloud adoption strategies.
• Improve CI/CD, automated testing and release safety.
• Promote cost-aware architecture and FinOps awareness.
• Lead adoption of reusable components for UK regulatory needs.
• Ensure threat modelling and privacy by design are integrated.
• Work with security and operations to address audit findings and controls.

Skills

C#

ASP.NET Core

RESTful APIs

Distributed systems

Asynchronous messaging

SQL-based data platforms

Azure services

CI/CD

DevSecOps

Threat modelling

Security by design

Architecture governance

Education

Degree in Computer Science or Software Engineering

Tools

Azure

Azure App Service

Azure Functions

Service Bus

Azure SQL

Cosmos DB

Job description

Pluxee seeks a Principal Engineer to provide technical leadership across .NET products and platforms in a hybrid role based in Milton Keynes. You will own end-to-end technical direction, shape architecture, drive governance, and lead cross-team collaboration to deliver secure, scalable software solutions for Payments, Discounts, Benefits and more.

You will stay hands-on with prototypes and reviews, mentor engineers, and ensure the alignment of architecture with business strategy and global