Senior C#/.NET Engineer – Front Office Liquidity & Risk

Margo Group; Greater London; Hybrid; GBP 90,000 - 140,000; Full time

Benefits offered by this job

Challenging projects

Front Office exposure

Career progression

Small team environment

Job summary

MARGO in London seeks a Senior C# / .NET Developer to build, modernize, and scale our front-office calculation engines. This is a hands-on, individual contributor role in a high-performance banking environment.

You will implement real-time feeds, RESTful APIs, and microservices while collaborating across Liquidity, Treasury & Risk IT. Strong C#/.NET, SQL Server, and DevOps experience are essential for delivering robust production systems.

Qualifications

• Proven experience as a Senior C# .NET Developer in demanding, performance-sensitive banking environments.
• Strong object-oriented design, asynchronous programming, and multithreading.
• Back-end experience building event-driven services, messaging systems, and Windows Services.
• MS SQL Server with Dapper expertise; lightweight ORM familiarity.
• DevOps pipelines and AI developer tools (Copilot/Claude) familiarity.

Responsibilities

• Design, build, and optimize high-performance back-end calculation engines using modern C# .NET.
• Develop asynchronous, message-driven microservices (Rebus) and Windows Services for distributed processing.
• Build and tune database objects, complex queries, and data access layers using MS SQL Server and Dapper.
• Implement real-time feeds and RESTful APIs using ASP.NET Web API and SignalR.
• Leverage LLMs and agentic AI workflows to accelerate testing, refactoring, and delivery.
• Deliver clean, testable code adhering to SOLID principles and CI/CD pipelines.

Skills

Senior C# .NET

Performance engineering

Event-driven design

Windows Services

MS SQL Server & Dapper

RESTful APIs (ASP.NET Web API)

SignalR

DevOps familiarity

Tools

Rebus

Git

TeamCity

Jenkins

Ansible

Dapper

MS SQL Server

Job description

MARGO in London seeks a Senior C# / .NET Developer to build, modernize, and scale our front-office calculation engines. This is a hands-on, individual contributor role in a high-performance banking environment.

You will implement real-time feeds, RESTful APIs, and microservices while collaborating across Liquidity, Treasury & Risk IT. Strong C#/.NET, SQL Server, and DevOps experience are essential for delivering robust production systems.