Office Add-ins Developer (Bengaluru)

Office Add-ins Developer Roles and Responsibilities Location: Bangalore Employment Type: Full Time / Contractual Experience: 3-6 Years Primary Skill: C#, .NET, Office Add-ins Development Secondary Skill: Node.js, JavaScript / TypeScript, Office.js Work Type: Hybrid / Office as per project requirement Job Summary We are looking for an experienced Office Add-ins Developer with strong hands-on expertise in C#, .NET, VSTO / COM Add-ins, and Microsoft Office application integration. The candidate should be able to design and develop stable, secure, and high-performance add-ins for Microsoft Office applications such as Word, Excel, PowerPoint, and Outlook. Knowledge of Node.js, JavaScript / TypeScript, and Office.js will be an added advantage for modern Office Web Add-ins development. Key Responsibilities Office Add-ins Development - Design and develop Microsoft Office add-ins using C#, .NET, VSTO, COM Add-ins, and Office Interop APIs. - Build add-in features for Microsoft Word, Excel, PowerPoint, and Outlook. - Work with Office object models, Ribbon customization, task panes, event handlers, and document-level operations. - Develop reusable components and libraries for Office add-in functionality. - Ensure add-ins are stable, responsive, and compatible with supported Office versions. C# / .NET Development - Develop application logic using C#, .NET Framework / .NET, and Visual Studio. - Work with Office events such as open, save, close, send, attachment handling, and user actions. - Implement document, email, attachment, and metadata-related workflows. - Write clean, maintainable, secure, and testable code. - Participate in technical design discussions and code reviews. Office Application Integration - Develop features for Outlook email compose, read, send, and attachment workflows. - Develop features for Word, Excel, and PowerPoint document processing. - Handle document properties, metadata, headers, footers, watermarks, labels, and user prompts where required. - Manage Office application behavior, add-in lifecycle, and event-driven functionality. - Debug and resolve issues related to Office APIs, COM exceptions, add-in loading, and runtime behavior. Node.js / Office.js Development - Develop or support modern Office Web Add-ins using Office.js, JavaScript / TypeScript, HTML, and CSS. - Work with Node.js for Office Web Add-in development and build tooling. - Work with add-in manifests, command buttons, task panes, and Office.js APIs. - Integrate Office Web Add-ins with backend APIs. - Debug add-ins across Microsoft 365, Outlook Web, and supported Office clients. API and Integration Development - Integrate add-ins with backend APIs and enterprise services. - Implement REST API communication, authentication, authorization, and token handling. - Handle API errors, retries, timeouts, and user-friendly error messages. - Work with Microsoft Graph API where required. - Ensure secure handling of tokens, user data, document metadata, and sensitive information. Performance and Code Quality - Optimize add-ins for startup time, responsiveness, and memory usage. - Ensure add-ins do not impact Office application performance. - Follow secure coding practices. - Implement proper logging, exception handling, and error diagnostics. - Troubleshoot performance issues, memory leaks, and application stability issues. Mandatory Skills - Strong hands-on experience in C# and .NET. - Experience in Microsoft Office Add-ins development. - Experience with VSTO, COM Add-ins, Office Interop APIs, and Office Object Model. - Good understanding of Microsoft Word, Excel, PowerPoint, and Outlook integration. - Experience with Ribbon customization, task panes, Office events, and Office UI integration. - Robust debugging and troubleshooting skills in Windows desktop application development. - Good understanding of REST APIs, authentication, authorization, and secure communication. - Ability to write clean, secure, scalable, and maintainable code. Good to Have Skills - Experience with Node.js, JavaScript / TypeScript, HTML, CSS, and Office.js. - Experience in developing Office Web Add-ins for Microsoft 365 / Outlook Web. - Experience with Microsoft Graph API. - Experience with npm, webpack, Vite, or similar JavaScript build tools. - Knowledge of Windows registry, certificates, Office Trust Center settings, and Office add-in load behavior. - Experience with SQL Server, MySQL, PostgreSQL, or similar databases. - Experience in cybersecurity, data protection, compliance, DLP, classification, or enterprise security products will be an added advantage. Qualification - B.E. / B.Tech / MCA / M.Tech in Computer Science, Information Technology, or related field. - 3-6 years of software development experience. - Minimum 2 years of hands-on experience in C# / .NET development. - Prior experience in Microsoft Office Add-ins, VSTO, COM Add-ins Offic