Microsoft Office Add-In Developer (.NET/C#)

Microsoft Office Add-In Developer (.NET/C#)

Office Add-ins | VSTO | Azure | Azure DevOps | Inside IR35 | ASAP Start | Contract until January 2027

We're partnering with a prestigious London-based law firm to secure an experienced Microsoft Office Add-In Developer to support the development, enhancement and maintenance of bespoke Office solutions used across the business.

This role is ideal for a developer with strong experience in .NET, C#, VSTO and custom Microsoft Office add-ins, alongside exposure to Azure-hosted solutions and Azure DevOps (ADO) pipelines.

While primarily remote, candidates should be willing and able to travel to London on occasion for stakeholder meetings, workshops and project activities.

Key Responsibilities

• Design, develop and maintain bespoke Microsoft Office add-ins and integrations.
• Build and support solutions using .NET, C# and VSTO technologies.
• Gather requirements and work closely with business stakeholders to deliver tailored solutions.
• Enhance and support existing Office-based applications and automation tools.
• Develop and maintain integrations with backend systems and services.
• Support Azure-hosted applications and services associated with Office solutions.
• Create and maintain CI/CD pipelines within Azure DevOps (ADO).
• Troubleshoot and resolve application issues, performance concerns and user-reported defects.
• Contribute to development standards, code quality and best practices.

Essential Skills & Experience

• Strong commercial experience with .NET and C# development.
• Proven experience developing and supporting Microsoft Office Add-ins.
• Expertise in VSTO (Visual Studio Tools for Office).
• Experience developing bespoke Office solutions for enterprise environments.
• Experience with Azure-hosted applications and services.
• Strong knowledge of Azure DevOps (ADO), including build and release pipelines.
• Experience with application troubleshooting, debugging and performance optimisation.
• Excellent stakeholder engagement and communication skills.

Desirable Skills

• Experience within legal, professional services or highly regulated environments.
• Knowledge of Microsoft 365 and Office Add-in technologies.
• Experience with PowerShell and automation.
• Familiarity with SharePoint, Microsoft Graph or other Microsoft ecosystem technologies.
• Experience working in Agile delivery teams.

Contract Details

• Role: Microsoft Office Add-In Developer
• Client: Leading London Law Firm
• Location: Remote with occasional travel to London
• IR35 Status: Inside IR35
• Start Date: ASAP
• Duration: Until 31st January 2027
• Rate: Competitive day rate

If you're an experienced .NET/C# Developer with strong expertise in VSTO, bespoke Office add-ins, Azure and Azure DevOps, we'd love to hear from you. Please send your latest CV, availability and required day rate for consideration.