Senior C# Developer

Reference: RP/C#_1790950628

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

GCS is acting as an Employment Business in relation to this vacancy.

£400.00 - £416.00
Per day
GBP400 - GBP416 per day + Inside IR35
Added 02/10/2026
Reference: RP/C#_1790950628

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