Senior C# Developer

GCS Recruitment; Greater London; Hybrid; GBP 65,000 - 88,000; Full time

Job summary

GCS Recruitment is seeking an experienced Senior C# Developer for a Tier 1 Investment Bank in Canary Wharf. You will contribute to modernising core desktop applications, moving to web-based and cloud-enabled platforms, and shaping future-state architecture within a large enterprise.

You'll work across the full SDLC, enhancing WPF/WinForms apps, building APIs, and integrating with Azure, while collaborating with stakeholders and architecture teams to deliver robust software solutions.

Qualifications

• Strong commercial experience developing applications using C#/.NET.
• Proven expertise with WPF or WinForms.
• Experience with SQL or Oracle and understanding of software design principles.

Responsibilities

• Develop and maintain enterprise-grade applications using C#
• Enhance and support existing WPF and WinForms applications
• Contribute to the migration of desktop applications towards web-based architectures
• Build and integrate APIs and backend services
• Write efficient SQL queries and stored procedures
• Collaborate with business analysts, architects and end users to understand requirements
• Participate in code reviews and promote development best practices
• Troubleshoot production issues and contribute to continuous improvement initiatives
• Support the adoption of Azure technologies as part of the broader cloud transformation strategy

Skills

C# / .NET

WPF / WinForms

SQL / Oracle

Azure

Software design principles

Job description

Contract Opportunity | Tier 1 Investment Bank | Canary Wharf

Overview

Our client, a Tier 1 Investment Bank based in Canary Wharf, is seeking an experienced C# Developer to join a strategic application modernisation programme. This role sits within a technology team responsible for evolving critical business applications, supporting a transition from legacy desktop solutions to modern web-based and cloud-enabled platforms.

The successful candidate will work across the full software development lifecycle, contributing to the enhancement of existing applications while helping shape the future-state architecture.

Key Information

Role: Senior C# Developer
Location: Canary Wharf, London (Hybrid Working)
Contract Length: 6 Months Initial Contract
Rate: £416 per day (Inside IR35)
Start Date: ASAP

The Programme

This role forms part of a wider transformation initiative focused on:

• Modernising legacy desktop applications
• Migrating technology platforms from on-premise infrastructure to Azure
• Supporting the transition from desktop-based solutions to web technologies
• Improving application performance, maintainability and scalability
• Delivering new functionality aligned to business and regulatory requirements

The successful contractor will work closely with development teams, business stakeholders and architecture functions to deliver high-quality software solutions within a complex enterprise environment.

Key Responsibilities

• Develop and maintain enterprise-grade applications using C#
• Enhance and support existing WPF and WinForms applications
• Contribute to the migration of desktop applications towards web-based architectures
• Build and integrate APIs and backend services
• Write efficient SQL queries and stored procedures
• Collaborate with business analysts, architects and end users to understand requirements
• Participate in code reviews and promote development best practices
• Troubleshoot production issues and contribute to continuous improvement initiatives
• Support the adoption of Azure technologies as part of the broader cloud transformation strategy

Required Skills & Experience

Essential

• Strong commercial experience developing applications using C#/.NET
• Proven expertise with WPF or Winforms
• Strong SQL or Oracle development skills
• Understanding of software design principles and development best practices
• Experience working within complex enterprise environments
• Experience working with Azure

Desirable

• Experience with JavaScript
• Exposure to React
• Experience contributing to application modernisation programmes
• Knowledge of Azure cloud technologies
• Experience within Financial Services, Investment Banking or Capital Markets environments

Personal Attributes

• Strong analytical and problem-solving skills
• Excellent communication and stakeholder management abilities
• Ability to work independently in a fast-paced environment
• Collaborative mindset and willingness to mentor junior developers
• Comfortable balancing support of legacy systems alongside modernisation initiatives