Senior .NET / C++ Software Engineer

Oliver Bernard; Greater London; Hybrid; GBP 90,000 - 100,000; Full time

Job summary

Oliver Bernard is seeking a Senior .NET Software Engineer to join a hybrid team, four days working from home. The role focuses on a mission-critical, regulated enterprise platform used across the UK, with ongoing modernization and cloud migration initiatives.

You’ll work across C#, C++, SQL Server and WinForms/WPF, maintain and improve complex workflows, mentor engineers, and contribute to performance, reliability and quality in a large-scale product.

Qualifications

• Experience with C# and C++ in large/ regulated systems.
• Strong SQL Server performance tuning.
• Experience with on-premise/ desktop software environments.
• Focus on stability, maintainability and quality.

Responsibilities

• Deliver regulatory and customer-driven enhancements across a complex enterprise platform.
• Work across C#, C++, SQL Server, and Windows-based technologies within a mature codebase.
• Own and improve critical filing and integration workflows.
• Diagnose and resolve complex performance and production issues.
• Contribute to modernisation and cloud migration initiatives.
• Improve code quality, testing, and maintainability through incremental engineering practices.
• Support release, deployment, and operational processes for production-critical software.
• Mentor junior engineers and contribute to technical best practices.

Skills

C#

C++

Tools

SQL Server

WinForms

WPF

Job description

Senior .NET Software Engineer – Hybrid 4 days WFH - £90,000-£100,000

We’re working with a highly respected SaaS and enterprise technology business looking for a Senior .NET / C++ Software Engineer to join a team responsible for software relied upon by some of the UK’s largest organisations.

This is a rare opportunity to work on a mission-critical platform operating within a highly regulated domain, where stability, performance, and engineering quality genuinely matter.

You’ll play a key role in maintaining and evolving a large-scale product used across the UK corporate tax landscape, while also contributing towards the long-term migration to a modern cloud-native platform.

What You’ll Be Doing:

• Deliver regulatory and customer-driven enhancements across a complex enterprise platform
• Work across C#, C++, SQL Server, and Windows-based technologies within a mature codebase
• Own and improve critical filing and integration workflows
• Diagnose and resolve complex performance and production issues
• Contribute to modernisation and cloud migration initiatives
• Improve code quality, testing, and maintainability through incremental engineering practices
• Support release, deployment, and operational processes for production-critical software
• Mentor junior engineers and contribute to technical best practices

Tech Environment:

• C++
• SQL Server / T-SQL
• WinForms / WPF
• XML / XSD / iXBRL
• CI/CD & automated testing
• AI-assisted development tooling including GitHub Copilot, Cursor, and Claude Code

What We’re Looking For:

• Strong commercial experience with both C# and C++
• Experience working within large, long-lived enterprise or regulated systems
• Deep understanding of SQL Server performance tuning and troubleshooting
• Experience supporting or evolving on-premise / desktop-based software environments
• Pragmatic engineering mindset with a focus on stability, maintainability, and quality
• Interest in modernisation, cloud migration, and AI-assisted development workflows
• Strong communication and collaborative problem-solving skills

What’s On Offer:

• Opportunity to work on genuinely business-critical software
• Exposure to modern cloud and AI engineering initiatives
• Collaborative engineering culture with strong technical ownership
• Long-term modernisation and transformation projects
• Stable, growing technology business with significant investment in engineering

If you enjoy solving complex engineering problems, improving mature systems, and building software that organisations truly depend on, we’d love to hear from you.

Senior .NET Software Engineer – Hybrid 4 days WFH - £90,000-£100,000