Senior C# .Net Developer

Location

London

Salary

Negotiable

Contract

Contract

Role: Senior C# .NET Developer
Location: London, UK
Working Pattern: Hybrid, 3 days per week onsite, Canary Wharf or Liverpool Street
Employment Type: Contract

Rate: £500 a day Inside IR35 via Umbrella

Role Overview

We are seeking experienced Senior C# .NET Developers to join a strategic technology transformation programme within a leading international banking environment.

The successful candidates will design, develop and enhance enterprise-grade applications supporting critical business functions across front-office, middle-office and back-office domains. They will work closely with Solution Architects, Technical Analysts, Business Analysts, Data Engineers and QA teams to deliver scalable, secure and high-performing solutions in a highly regulated environment.

Key Responsibilities

• Design, develop and maintain enterprise applications using C# and .NET.
• Develop scalable, secure and high-performance APIs, services and distributed applications.
• Work with Technical Analysts and business stakeholders to translate requirements into technical solutions.
• Contribute to solution architecture, technical design and code reviews.
• Develop RESTful APIs and integration services.
• Implement monitoring, logging and error handling.
• Work with relational and non-relational databases.
• Develop automated unit, integration and regression tests.
• Support CI/CD and DevOps practices.
• Troubleshoot production issues and perform root-cause analysis.
• Follow engineering, security and development standards.
• Participate in Agile delivery.
• Support application modernisation and cloud adoption.

Mandatory Skills

• Strong commercial C#/.NET development experience
• .NET Core / .NET 6+
• ASP.NET Core / Web API
• REST APIs and microservices
• SQL Server, including complex queries, stored procedures and optimisation
• Entity Framework / ORM
• Object-oriented design and design patterns
• Distributed systems and enterprise integration
• Unit and automated testing
• Azure DevOps, Git and CI/CD
• Agile/Scrum delivery
• Strong troubleshooting and problem-solving capability
• Good stakeholder communication

Desirable

• Banking, Capital Markets or Financial Services
• Azure
• Docker / Kubernetes
• Kafka, RabbitMQ or Azure Service Bus
• Event-driven architectures
• React / Angular
• Cloud-native development
• Application observability and performance engineering
• DevSecOps and secure coding

Preferred Stack

C# | .NET Core/.NET 8 | ASP.NET Core | REST APIs | SQL Server | Entity Framework | Azure | Azure DevOps | Git | Docker | Kubernetes | Kafka | Redis | JSON/XML | Swagger/OpenAPI

Disclaimer

This vacancy is being advertised by either Advanced Resource Managers Limited, Advanced Resource Managers IT Limited or Advanced Resource Managers Engineering Limited ("ARM"). ARM is a specialist talent acquisition and management consultancy. We provide technical contingency recruitment and a portfolio of more complex resource solutions. Our specialist recruitment divisions cover the entire technical arena, including some of the most economically and strategically important industries in the UK and the world today. We will never send your CV without your permission. Where the role is marked as Outside IR35 in the advertisement this is subject to receipt of a final Status Determination Statement from the end Client and may be subject to change.

Apply Job reference 131016_1792067982 Date posted 15 October 2026 Sector Information Technology

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