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.