Top 100 Power Apps Interview Questions and Answers

Wednesday, January 13, 2021

Top 100 Power Apps Interview Questions and Answers

Power Apps Interview Master Guide

Beginner to Advanced (100+ Questions Strategy)

🚀 Fundamentals 🎨 Canvas ⚙️ Model-Driven

SECTION 1: Power Apps Fundamentals

Q1. What is Power Apps and what problem does it solve?

Answer: Power Apps is a low-code application development platform by Microsoft that allows users to build business applications quickly without traditional coding.

It solves problems such as slow application development, heavy dependency on full-stack developers, and lack of agility in business processes. It enables rapid UI creation and easy integration with data sources.

Q2. What types of Power Apps are available?

  • Canvas Apps: UI-first apps with fully customizable layout (Pixel Perfect).
  • Model-Driven Apps: Data-driven apps with standardized UI based on Dataverse.
  • Custom Pages: Canvas-style pages embedded inside Model-Driven Apps.

Q3. When should Power Apps be used instead of traditional development?

Power Apps is best when:

  • Time-to-market is critical (Rapid Development).
  • Business logic is UI-centric.
  • Frequent changes are expected.
  • Mobile and tablet access is required immediately.

Note: Traditional development is better for heavy computation.

Q4. Explain Power Fx in detail.

Power Fx is the formula language used in Power Apps, inspired by Excel. It is declarative, meaning developers describe what they want (e.g., "Show this button"), not how to do it step-by-step.

Q5. What is Delegation in Power Apps?

Answer: Delegation means offloading data operations (filtering, sorting, searching) to the server (Data Source) instead of processing them locally on the device.

Why it matters: Without delegation, Power Apps only retrieves the first 500-2000 records, leading to incorrect data in large datasets.

Rapid Fire: Fundamentals (Q6-Q10)

  • Q6. Connectors: Bridges that define how Power Apps communicates with services like SQL, SharePoint, or APIs.
  • Q7. Power Apps Player: The container app that allows users to run Canvas Apps on iOS/Android.
  • Q8. Lifecycle: Design → Testing → Publishing → Sharing → Maintenance.
  • Q9. Limitations: Delegation limits, API request limits, and complex UI performance on older devices.
  • Q10. One Sentence Definition: "A low-code platform for rapidly building responsive business apps with minimal dev effort."

SECTION 2: Canvas Apps (UI & Logic)

Q11 & Q12. Canvas App Basics

Why "Canvas"? Because it provides a blank canvas where every pixel (position, size, color) is fully customizable by the developer.

Best Choice When: You need custom UX/Branding, mobile-first design, or complex user-driven interactions.

Q16. Explain Galleries.

Galleries are container controls used to display repeating records from a data source. They are optimized for scrolling, filtering, and displaying lists of items.

Q18. Patch() vs SubmitForm()?

SubmitForm Patch
Easy to use, built-in validation. Granular control, allows partial updates.
Tied strictly to a Form control. Can update data from any control/logic.

Q20. Local vs Global Variables?

  • Local (UpdateContext): Scoped to a single screen. Performance-friendly.
  • Global (Set): Available throughout the entire app. Use sparingly to avoid complexity.

Q21. Why use Collections?

Collections store data locally in the device's memory. This:

  1. Reduces network calls (Chattiness).
  2. Minimizes delegation issues (by processing data locally).
  3. Enables complex sorting/joining of data.

Q29. What is the With() function?

With() creates temporary scoped variables (named values) for a specific formula. It makes code readable and avoids recalculating the same value multiple times.

Q31. How to optimize Gallery Performance?

  • Limit the number of controls in the template.
  • Use collections to cache data.
  • Avoid heavy lookups inside the gallery items.
  • Disable "Flexible Height" if not needed (rendering cost).

SECTION 3: Model-Driven Apps

Q46 & Q48. Model-Driven Concept

Model-Driven Apps are Configuration-First. The UI is generated automatically based on your Dataverse data model (Tables, Relationships).

Canvas vs Model-Driven: Canvas is Pixel-Perfect (UX focus). Model-Driven is Process-Perfect (Data focus).

Core Components (Q49-Q52)

  • Forms: Define how specific records are Create/Edited.
  • Views: Define lists/grids of records with filtering and sorting.
  • Sitemap: The navigation bar structure (Left menu).
  • Dashboards: Visual overview of data using Charts and Lists.

SECTION 4: Custom Pages

Q71. What are Custom Pages?

Custom Pages bring the power of Canvas Apps inside Model-Driven Apps. They allow you to build pixel-perfect screens that act as a page within the model-driven navigation.

Q73. Custom Pages vs Forms?

Standard Model-Driven Forms are restricted to the data structure. Custom Pages allow flexible UI (pop-ups, multiple data sources, custom layout) while staying in the same app session.

SECTION 5: Performance & ALM

Q91. What causes slow apps?

  • Heavy Formulas: Complex logic in OnStart or OnVisible.
  • Large Datasets: Not using delegation or pagination.
  • Control Count: Too many controls on a single screen (DOM weight).
  • N+1 Issue: Making repeated server calls inside a loop (ForAll).

Q99. Senior Level Best Practice?

Answer: "Design for maintainability and scalability, not just functionality."

This means using Components, naming conventions, efficient delegation, and proper ALM (Solutions) from day one.

Summary

Canvas Apps = UX | Model-Driven = Process | Custom Pages = The Hybrid Future

 

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