Senior C#/.Net Developer

ARM International; Greater London; Hybrid; GBP 80,000 - 105,000; Part time

Job summary

ARM International in London is seeking experienced Senior C# .NET Developers to join a strategic technology transformation programme within a leading international banking environment.

Design, develop and enhance enterprise-grade applications across front-, middle- and back-office domains. Collaborate with architects, analysts, data engineers and QA to deliver scalable, secure, high-performing solutions in a regulated setting.

Qualifications

• Must have proven experience with senior C#/.NET development in banking or regulated environments.
• Experience delivering enterprise-grade applications across front, middle and back offices.

Responsibilities

• Design, develop and maintain enterprise applications using C# and .NET.
• Develop scalable, secure APIs, services and distributed apps.
• Translate requirements with analysts and stakeholders into technical solutions.
• Contribute to solution architecture, 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.
• Support modernization and cloud adoption.

Skills

.NET Core / .NET 6+

ASP.NET Core / Web API

REST APIs and microservices

SQL Server

Entity Framework / ORM

Object-oriented design

Distributed systems

Unit testing

Azure DevOps

Git and CI/CD

Troubleshooting

Stakeholder communication

Kafka / RabbitMQ / Service Bus

Event-driven architectures

React / Angular

Observability and performance

Tools

Azure DevOps

Job description

6-Month contract – Inside IR35 – up to £500 per day

London based – hybrid working – 3 days a week onsite

Banking sector – must have previous experience

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.
• Support application modernisation and cloud adoption.

Mandatory Skills

• .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
• Strong troubleshooting and problem-solving capability
• Good stakeholder communication
• Kafka, RabbitMQ or Azure Service Bus
• Event-driven architectures
• React / Angular
• Application observability and performance engineering