4) Technical and professional questions (the ones that decide it)
This is where US interviews get blunt. They’ll test whether you can build modern SharePoint Online solutions, and whether you understand the “blast radius” of your choices: permissions, performance, lifecycle, and compliance.
Q: Explain the difference between SPFx extensions and web parts. When would you choose each?
Why they ask it: They want to know if you can pick the right SPFx tool for the job.
Answer framework: Compare–Choose–Tradeoff: define both, pick a scenario, explain tradeoffs.
Example answer: “A web part is for content on a page—dashboards, search UI, forms, data views. An SPFx extension changes the experience around the page, like an Application Customizer for headers/footers or a Field Customizer for list rendering. If I need a consistent banner with environment warnings across sites, I’ll use an Application Customizer. If I need a reusable component inside pages with configurable properties, I’ll use a web part. I decide based on scope, deployment impact, and how much I’m altering the native UX.”
Common mistake: Treating extensions as ‘just another web part’ and ignoring their global impact.
Q: How do you authenticate from an SPFx web part to Microsoft Graph, and what permissions model do you prefer?
Why they ask it: Graph is everywhere; they want secure, tenant-friendly patterns.
Answer framework: “Flow of auth”: user context, token acquisition, permission type, admin consent.
Example answer: “In SPFx I typically use the MSGraphClient or AadHttpClient, depending on the endpoint. I prefer delegated permissions when the user’s identity should drive access, and I keep scopes minimal—least privilege. For app-only scenarios, I’m careful: it’s powerful but risky, so I justify it with a clear business need and implement strict access controls and auditing. I also plan for the admin consent process and document exactly what the app can read or write.”
Common mistake: Asking for broad Graph permissions ‘just to make it work.’
Q: What’s your approach to performance in SharePoint Online—especially for SPFx Developer work?
Why they ask it: Slow pages kill adoption; they want someone who designs for real users.
Answer framework: “Measure–Optimize–Guardrails”: how you measure, what you optimize, how you prevent regressions.
Example answer: “First I measure: bundle size, network calls, and render timing in the browser. Then I optimize by code-splitting, lazy-loading heavy components, caching Graph calls where appropriate, and avoiding chatty list queries. I also use pagination and server-side filtering instead of pulling thousands of items client-side. Finally, I add guardrails in CI—bundle analysis and lint rules—so performance doesn’t degrade quietly over time.”
Common mistake: Talking only about ‘minification’ and ignoring network and data access patterns.
Q: How do you design permissions for a SharePoint site that contains sensitive content but still needs broad collaboration?
Why they ask it: Permissions are where SharePoint projects go to die.
Answer framework: “Layers”: site design, groups, sharing settings, labels/retention, auditing.
Example answer: “I start with a clear audience model: visitors, members, owners, and any restricted subgroups. I avoid breaking inheritance unless there’s a strong reason, and I prefer group-based access via Microsoft 365 groups or security groups. For sensitive content, I combine permissions with sensitivity labels and conditional access policies, because permissions alone don’t stop data from leaving. I also set up periodic access reviews and monitor sharing and audit logs.”
Common mistake: Solving everything with unique permissions on folders and documents.
Q: What’s the difference between classic and modern SharePoint customization, and what do you avoid in 2026?
Why they ask it: They want modern patterns and long-term maintainability.
Answer framework: “Then–Now–Rule”: what used to work, what works now, your rule of thumb.
Example answer: “Classic customization leaned on master pages, script injection, and heavy JS on pages. Modern SharePoint Online pushes you toward SPFx, Power Platform, and supported APIs. In 2026 I avoid unsupported script injection patterns and anything that fights the modern page model. If a requirement can be met with out-of-the-box web parts, list formatting, or Power Automate, I’ll use that before custom code—then reserve SPFx for real product-grade needs.”
Common mistake: Bragging about legacy techniques that create upgrade and security problems.
Q: How do you handle CI/CD for SPFx solutions in a US enterprise environment?
Why they ask it: They want to know if you can ship safely with governance.
Answer framework: “Pipeline story”: build, test, package, deploy, validate.
Example answer: “I use Azure DevOps or GitHub Actions to build and package the solution, run unit tests, and enforce linting. Artifacts are versioned, and deployments go through environments—dev, test, prod—with approvals. For deployment, I use the App Catalog and control whether it’s tenant-wide or site-scoped based on risk. After deployment, I validate key pages and monitor telemetry so we catch issues quickly.”
Common mistake: Treating deployment as ‘upload the .sppkg and hope.’
Q: What’s your strategy for migrating from SharePoint on-prem to SharePoint Online?
Why they ask it: Many US orgs are still mid-migration; they need realistic planning.
Answer framework: “Discover–Decide–Move–Stabilize”: inventory, decide what to keep, migrate, then fix adoption.
Example answer: “I start with discovery: site inventory, customizations, workflows, and business-critical content. Then I decide what to modernize versus lift-and-shift—especially replacing legacy workflows with Power Automate or Azure Functions. For the move, I plan waves, validate permissions and metadata, and run pilot migrations with business owners. Stabilization is where the real work is: search tuning, training, and cleaning up broken links and old custom code.”
Common mistake: Promising a ‘simple’ migration without addressing customizations and workflows.
Q: In the US, how do you think about compliance requirements like retention and eDiscovery in SharePoint Online?
Why they ask it: They need you to understand Microsoft Purview realities, not just build UI.
Answer framework: “Map requirement to control”: requirement → Purview feature → implementation detail.
Example answer: “I translate requirements into Purview controls: retention labels/policies for lifecycle, sensitivity labels for classification, and eDiscovery holds when legal needs it. In SharePoint, that means designing content types and metadata so labels can be applied consistently, and ensuring users don’t bypass controls with uncontrolled sharing. I also coordinate with compliance on audit logging and documentation, because in regulated environments the paper trail matters.”
Common mistake: Treating compliance as ‘someone else’s job’ and ignoring how your design affects it.
Q: What would you do if Microsoft Graph starts throttling your SPFx web part in production?
Why they ask it: This is a real failure mode; they want calm, practical debugging.
Answer framework: Incident–Mitigation–Fix–Prevention: stabilize first, then correct.
Example answer: “First I’d confirm it’s throttling by checking response headers and correlating with telemetry. Mitigation might be reducing call frequency, adding caching, and implementing exponential backoff with retries. Then I’d fix the root cause—batch requests, reduce over-fetching, and ensure we’re using server-side filtering. Finally, I’d add monitoring and load testing so we catch it before users report it.”
Common mistake: Saying ‘Graph is down’ and stopping there—throttling is often self-inflicted.
Q: How do you decide between Power Automate, Azure Functions, and custom SPFx logic for a business process?
Why they ask it: They want architecture judgment, not tool loyalty.
Answer framework: “Complexity ladder”: start with lowest complexity that meets requirements.
Example answer: “If it’s a straightforward approval or notification with standard connectors, Power Automate is usually the fastest and most maintainable. If we need complex logic, heavy transformations, or robust error handling at scale, I’ll use Azure Functions or Logic Apps. SPFx is great for the UI layer, but I avoid burying business logic in the client when it needs reliability and auditing. The decision is driven by scale, security, and who will maintain it.”
Common mistake: Building everything in code because it feels ‘more developer.’