Principal C# Engineer/Snr Dev Lead

The consultant will operate as a senior development lead and principal-level C#/.NET engineer within Risk, Product Control and ESG IT. The role combines hands-on engineering with solution design, stream leadership, technical oversight and delivery accountability across a CTB portfolio.

The role will support new product onboarding, feature delivery, methodology changes, platform enhancements, service modernisation and selected greenfield components. The consultant is expected to remain substantially hands-on, contributing approximately 25%-50% as an individual contributor, with the balance focused on coordination, design governance, mentoring, dependency management and delivery execution.

The technology stack is primarily C#/.NET, supported by MongoDB, SQL Server data warehouse components, enterprise messaging and OpenShift-based container platforms. The role will use the bank's internal developer platform capabilities to deliver secure, resilient, observable and portable services aligned to modern engineering and platform standards., * Lead technical analysis, solution design and hands-on development of applications, services, APIs, event-driven components, batch processes and platform-aligned capabilities.

• Act as a C#/.NET SME, setting engineering direction and ensuring solutions are clean, maintainable, testable and aligned to modern .NET practices, SOLID principles and appropriate design patterns.
• Produce and review solution designs covering service boundaries, contracts, data models, integration patterns, idempotency, resilience, security, observability and operational supportability.
• Contribute directly to code delivery while reviewing implementation approaches, pull requests and engineering standards across the team.
• Lead delivery streams across internal and external resources, including work breakdown, estimation, sprint planning, technical triage, dependency management, risk management and stakeholder reporting.
• Apply and extend internal developer platform and platform engineering patterns, including shared .NET libraries, reusable templates, golden paths, automated delivery, configuration and operational dashboards.
• Support migration from Windows-hosted services to OpenShift, including containerisation, Helm-based deployment, Kubernetes orchestration, scaling, storage integration, service mesh alignment and production readiness.
• Design and optimise integrations across MongoDB, SQL Server/data warehouse components, REST APIs, enterprise data sources and messaging platforms such as ActiveMQ, Kafka or Redpanda.
• Design event-driven solutions using appropriate messaging patterns including publish/subscribe, competing consumers, retries, dead-letter handling, schema/version management and effectively-once processing where required.
• Use AI-enabled engineering tooling responsibly to improve delivery productivity, including integrated agentic coding assistants, prompt engineering, code review support and where appropriate, agentic workflow patterns and MCP-based integrations.
• Mentor developers and improve team capability across C#/.NET, OpenShift, MongoDB, SQL, messaging, platform engineering and modern engineering practices.
• Ensure appropriate unit, integration, contract, regression, performance and system testing is applied, and support UAT, release preparation, cutover and early-life support.
• Liaise with business users, methodology teams, delivery managers, support teams, platform teams and other ISD teams to ensure delivery remains aligned to business priorities, platform standards and control expectations.
• Adhere to development standards, SDLC processes, change control, information security and operational resilience expectations.

• Extensive experience as a senior developer, technical lead, principal engineer, stream lead or development lead in a complex enterprise technology environment.
• Strong hands-on C#/.NET development experience, with the credibility to lead senior engineers while still contributing directly to delivery.
• Experience producing solution designs, guiding implementation and coordinating work across multiple developers, workstreams or delivery partners.
• Experience delivering CTB change across production-facing systems where resilience, supportability, auditability, security and controlled change are important.
• Experience applying engineering best practice including loose coupling, contract-first design, idempotency, automated testing, secure coding, observability and operational readiness.
• Experience leading people to deliver, including mentoring, work allocation, delivery tracking, quality review and constructive challenge, while remaining substantially hands-on.
• Experience working with business and IT stakeholders in a pressured delivery environment, ideally within financial services or another regulated industry.

Technical Knowledge/Skills

• Expert knowledge of C# and strong knowledge of .NET Framework, .NET Core and modern .NET.
• Strong understanding of solution design, service boundaries, design patterns, SOLID principles, microservice architecture and scalable service design.
• Strong experience developing REST APIs and integration patterns, including contract-first API design, versioning, validation, error models and backward compatibility.
• Strong document database knowledge, preferably MongoDB, including schema design, indexing, aggregation, performance tuning, consistency trade-offs and operational considerations.
• Strong relational database and SQL skills, including design, optimisation and data warehouse interaction.
• Strong knowledge of enterprise messaging and event-driven architecture, ideally ActiveMQ, Kafka, Redpanda or equivalent, including message contracts, ordering, retries, DLQs and consumer resilience.
• Strong knowledge of container platforms and cloud-native architecture, preferably OpenShift/Kubernetes, including Helm deployment, orchestration, scaling, service discovery, configuration and runtime operations.
• Good knowledge of Kubernetes ecosystem capabilities including KEDA or equivalent event-driven scaling, Istio or equivalent service mesh, ingress/routing, secrets/configuration management and persistent volume/claim patterns using storage platforms such as Portworx.
• Good knowledge of automated testing and delivery practices, including unit, integration and contract testing, CI/CD pipelines, source control, quality gates and container image management.
• Practical experience with tooling such as JIRA, Bamboo, Git/Bitbucket, NuGet and container image registries.
• Knowledge of platform engineering practices, internal developer platforms, golden paths, reusable templates, paved-road adoption and self-service delivery capabilities.
• Knowledge and practical experience of AI-enabled development tooling, integrated agentic coding assistants and prompt engineering; experience designing agentic workflows or MCP-enabled integrations is desirable.
• Risk IT, Product Control IT, ESG IT, regulatory technology or financial-services domain experience is desirable.