Frontend & DSA Top 20 Interview Questions

1. Debounce and Throttle with DSA twistProblem: Implement a debounce function, and then solve a problem where you need to limit API calls using debounce when the user types quickly in a search bar.

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2. Infinite Scroll Loader

Problem: Given a huge array (e.g., 10M items), implement a lazy loader that loads items as the user scrolls, with O(1) space and time efficiency.

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3. Implement a Deep Clone

Problem: Implement deep cloning of a nested object, handling edge cases like functions, dates, cyclic references.

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4. Longest Substring Without Repeating Characters

LeetCode 3 Variant:

Solve using sliding window, optimize it to O(n) time.

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5. Design a Scheduler (like setTimeout but controllable)

Problem: Implement a TaskScheduler class where tasks are scheduled and can be paused, resumed, and canceled.

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6. Auto-Save using setInterval & Debounce combo

Problem: User is typing in a text editor. Auto-save must trigger every 5s of inactivity. Combine setInterval + debounce efficiently.

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7. Merge Intervals in a Stream

Problem: Given intervals coming in as a stream, merge overlapping ones and return…