Excel AI Addin Engineer

React

Office Add-ins

Type Script

Excel JS API

AI

Office 365

We’re building something most people don’t expect: an AI-powered experience that lives right inside Microsoft Excel. As a Software Engineer on this team, you’ll develop React-based Excel Add-ins that connect our AI platform directly to the tool millions of users already live in every day. Think of it as bringing the power of machine learning to the spreadsheet, no context-switching, no separate app, just intelligent capabilities woven into the workflow users already know.

This is a unique front-end engineering role with serious AI exposure. You’ll work across the Microsoft Office Add-in ecosystem, build rich task pane and custom function experiences, and integrate with our AI/ML backend services to surface predictions, recommendations, and generative content right in the cells, panels, and ribbons that users interact with. If you love building products at the intersection of familiar tools and cutting-edge technology, this is your opportunity.

Build AI-Powered Excel Experiences

• Design and develop React-based Excel Add-ins using the Office JS API, custom functions, and task panes that bring AI capabilities to end users inside their spreadsheets.
• Integrate with our AI platform to surface model outputs, predictions, classifications, summaries, generated content, directly within Excel workflows.
• Build intuitive UI that makes complex AI interactions feel simple: prompt inputs, streaming results, inline data enrichment, and contextual recommendations.
• Be part of opportunities to expand the AI platform across other Office products such as outlook.

Own the Add-in Architecture

• Architect clean, maintainable React applications within the constraints and opportunities of the Office Add-in framework.
• Handle data flow between Excel workbooks, our cloud APIs, and the AI inference layer, managing state, caching, and error handling gracefully.
• Ensure add-ins perform well across Excel for Desktop, Excel Online, and Mac, accounting for platform-specific quirks and capabilities.
• Champion best practices for Office Add-in development: manifest configuration, authentication (SSO via MSAL), side loading, and App Source distribution.
• Partner with AI/ML engineers to define API contracts and shape how model outputs get presented to non-technical users.
• Work closely with product owners and UX designers to translate AI capabilities into spreadsheet-native interactions that feel natural.
• Participate in agile ceremonies, standups, sprint planning, retrospectives, shipping high-value features in short iterations.
• Share knowledge, conduct code reviews, and help the team level up on Office platform development.
• Experiment with new Office platform capabilities, Future Copilot extensibility, Office Scripts, Excel custom data types, to unlock new AI use cases.
• Prototype new ideas quickly; a working demo in Excel is worth more than a deck of slides.
• Stay current with the evolving Microsoft 365 developer ecosystem and the latest in AI tooling and frameworks.

Must-Haves

• 3+ years of professional front-end development experience with React (hooks, context, component architecture).
• Experience with the Microsoft Office Add-in framework (Office JS API), or a strong willingness and aptitude to ramp quickly.
• Solid understanding of REST APIs, async data flows, and client-side state management.
• Familiarity with authentication patterns in Microsoft ecosystems (MSAL, Azure AD / Entra ).
• Bachelor’s degree in Computer Science, Engineering, or related field, or equivalent practical experience.
• Strong communicator who thrives in cross-functional, agile teams.

Nice-to-Haves

• Prior experience building Excel Add-ins, custom functions, or Office Scripts.
• Exposure to AI/ML concepts, prompt engineering, model inference APIs, or building interfaces on top of LLM outputs.
• Experience with the broader Office 365 / Microsoft 365 developer platform (Microsoft Graph API, Teams apps, SharePoint Framework).
• Familiarity with testing frameworks (Jest, Playwright, Cypress) and CI/CD pipelines for add-in deployment.
• Experience publishing add-ins to App Source or managing enterprise sideload…