Technologies Coding Problems Bookmarks Learning Paths

Technologies Coding Problems Bookmarks Learning Paths

AI-powered interview preparation platform. Practice with curated questions, mock interviews, and personalized learning paths to crack your dream tech interview.

Quick Links

Technologies
Saved Questions
Pricing

Company

About Us
Contact Us

Legal

Privacy Policy
Terms of Use

© 2026 nextRound. All rights reserved.

Discuss stack reconciler. | Reconciliation | react Interview Questions | NextRound.in

Questions

5 of 13

1What is reconciliation in React?

2What is react fibre?

3What is fibre in react fiber?

4Discuss fibre lifecycle.

5Discuss stack reconciler.

6What is concurrent rendering in react?

7How does React Fiber improve the rendering performance?

8What is the purpose of the `dangerouslySetInnerHTML` attribute in React?

9When rendering a list what is a key and what is its purpose?

10What are low and high-priority updates?

11What is work in progress tree in react fibre?

12Is React Fiber backward compatible with previous versions of React?

13How does React Fiber handle errors?

react

State and Props

Class Components

Function Components

Lifecycle functions

Performance Optimisation

05 / 13

Discuss stack reconciler.

Difficulty: 6/10

reconciliation, fiber, rendering pipeline

1
The previous reconciliation algorithm, known as Stack Reconciler, worked in a recursive manner, blocking the main thread during the update process.
2
This sometimes led to performance issues, especially when dealing with complex applications with frequent updates.
3
Fibre aims to solve these problems by introducing a more efficient reconciliation process.

Scenario Questions

0-2 years experience

1If you add a new component to a React app that uses the default stack reconciler, what steps does React take to render it to the DOM?
2When you call setState in a class component rendered with the stack reconciler, which part of the UI updates first and why?

2-5 years experience

1You notice a component's UI isn’t updating after a prop change. How would you investigate whether the stack reconciler is incorrectly bailing out, and what could cause that behavior?

Follow-up Questions

Can you describe how React decides whether to reuse an existing DOM node during reconciliation?
What would change if you switched the app to use the fiber reconciler instead of the stack reconciler?
How does the reconciler interact with React's scheduling priorities?

Sharethis question

Share via WhatsApp, X, Facebook, LinkedIn or copy link. Open Graph preview enabled.

2During a migration to React 18 concurrent features, the team keeps the stack reconciler for some parts of the app. What trade‑offs should they consider, and how might the reconciler affect performance?

5-8 years experience

1Explain how the stack reconciler’s depth‑first traversal impacts memory usage in a large component tree, and propose a strategy to mitigate any issues.
2If you need to build a custom renderer that must support both the stack and fiber reconciler, what design decisions would you make to keep the reconciler logic reusable and performant?

8+ years experience

1Your organization plans to replace the legacy stack reconciler with the fiber reconciler across multiple products. What architectural changes, testing strategies, and migration steps would you recommend to minimize risk?
2When designing a cross‑team UI library used in both web and native environments, how does the choice of reconciler (stack vs fiber) influence the library’s API surface and long‑term maintenance?