DevPrep
  • Interview Prep
  • Projects
  • Resources
  • Pricing
  • About Us
Submit Question
DevPrep
  • Pricing
  • About Us
Submit Question

Practice

  • JavaScript
  • DSA
  • Machine Coding
  • System Design

Resources

  • Learning Tracks
  • Articles
  • Roadmaps
  • Compare Concepts
  • Glossary
  • Developer Tools
  • All Questions

Company

  • About
  • Pricing

Legal

  • Privacy Policy
  • Terms of Service
DevPrep

© 2026 DevPrep. All rights reserved.

Interview Questions

Practice real technical interview questions. Filter by difficulty, type, or category.

Google Interview Prep

Top questions asked at Google

FAANG Top 75

Must-know problems for FAANG

DSA Crash Course

Master fundamentals fast

Frontend Mastery

React, JS & CSS deep dives

System Design Guide

Scalability & architecture

View All Tracks

Showing 1–20 of 66 questions

#Category
1Machine Coding: Build a Smart Task Scheduler with CooldownFrontend EngineeringMediumJavaScript27
Machine Coding: Build a Smart Task Scheduler with CooldownMedium
Frontend EngineeringJavaScript27
2Machine Coding: AI-IDE Task SchedulerFrontend EngineeringMediumMachine Coding6
Machine Coding: AI-IDE Task SchedulerMedium
Frontend EngineeringMachine Coding6
3Machine Coding: Fix the Stale Closure BugFrontend EngineeringMediumMachine Coding9
Machine Coding: Fix the Stale Closure BugMedium
Frontend EngineeringMachine Coding9
4Machine Coding: High-Performance Search AutocompleteFrontend EngineeringHardMachine Coding16
Machine Coding: High-Performance Search AutocompleteHard
Frontend EngineeringMachine Coding16
5useArray()Frontend EngineeringMediumJavaScript3
useArray()Medium
Frontend EngineeringJavaScript3
6useUpdateEffect()Frontend EngineeringMediumJavaScript14
useUpdateEffect()Medium
Frontend EngineeringJavaScript14
7useTimeout()Frontend EngineeringMediumJavaScript11
useTimeout()Medium
Frontend EngineeringJavaScript11
8Mastering the useFocus Hook: From React Fundamentals to Production-Grade ArchitectureFrontend EngineeringMediumJavaScript4
Mastering the useFocus Hook: From React Fundamentals to Production-Grade ArchitectureMedium
Frontend EngineeringJavaScript4
9Your Invoice Generator Must Format Currency Amounts With Thousands SeparatorsFrontend EngineeringMediumJavaScript8
Your Invoice Generator Must Format Currency Amounts With Thousands SeparatorsMedium
Frontend EngineeringJavaScript8
10Your Accessibility Audit Tool Needs to Collect All Unique HTML Tag Names in a DocumentFrontend EngineeringMediumJavaScript1
Your Accessibility Audit Tool Needs to Collect All Unique HTML Tag Names in a DocumentMedium
Frontend EngineeringJavaScript1
11The "Infinity Ledger" Addition AlgorithmFrontend EngineeringEasyJavaScript1
The "Infinity Ledger" Addition AlgorithmEasy
Frontend EngineeringJavaScript1
12Your Scientific Calculator Handles Signed Arbitrary-Precision Addition Including NegativesFrontend EngineeringMediumJavaScript2
Your Scientific Calculator Handles Signed Arbitrary-Precision Addition Including NegativesMedium
Frontend EngineeringJavaScript2
13Build an Asynchronous Value Container That Chains Handlers and Propagates ErrorsFrontend EngineeringMediumJavaScript2
Build an Asynchronous Value Container That Chains Handlers and Propagates ErrorsMedium
Frontend EngineeringJavaScript2
14Your Polling Service Needs a Controllable Repeating Timer With Start, Pause, and StopFrontend EngineeringMediumJavaScript2
Your Polling Service Needs a Controllable Repeating Timer With Start, Pause, and StopMedium
Frontend EngineeringJavaScript2
15Wrap DOM Event Listeners Into a Subscribable Stream With Automatic CleanupFrontend EngineeringEasyJavaScript6
Wrap DOM Event Listeners Into a Subscribable Stream With Automatic CleanupEasy
Frontend EngineeringJavaScript6
16Your Template Engine Safely Accesses Deeply Nested Config Values Without Crashing on Missing KeysFrontend EngineeringMediumJavaScript0
Your Template Engine Safely Accesses Deeply Nested Config Values Without Crashing on Missing KeysMedium
Frontend EngineeringJavaScript0
17Build a Query String Parser and Builder for Environments Without Native URLSearchParamsFrontend EngineeringHardJavaScript2
Build a Query String Parser and Builder for Environments Without Native URLSearchParamsHard
Frontend EngineeringJavaScript2
18Your Search Engine Combines Results From Multiple Pre-Sorted Indexes Into One Ranked ListFrontend EngineeringEasyJavaScript3
Your Search Engine Combines Results From Multiple Pre-Sorted Indexes Into One Ranked ListEasy
Frontend EngineeringJavaScript3
19Beyond useEffect: Why Staff Engineers use useSyncExternalStore for State TrackingFrontend EngineeringHardMachine Coding267
Beyond useEffect: Why Staff Engineers use useSyncExternalStore for State TrackingHard
Frontend EngineeringMachine Coding267
20Implement Fan-In Pattern: Merge Multiple ChannelsBackend EngineeringMediumMachine Coding214
Implement Fan-In Pattern: Merge Multiple ChannelsMedium
Backend EngineeringMachine Coding214

Showing 1–20 of 66 questions