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Updated weekly · Last refresh Sep 25

Top 50 Frontend Engineer Interview Questions

The 50 most important questions to prepare for Frontend Engineer interviews. Questions from real interview reports rank first. Updated daily.

50questions
~21htotal time
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1
javascriptStart here. 8 questions · ~200 min
2
Recursion6 questions · ~150 min
Flatten a Nested ArrayEasy
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Recently asked

Flatten a nested array into a single list using recursion or an explicit stack while preserving left-to-right order.

RecursionStackArraysSentinelOneBask HealthSolytics Partners
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3
Hash Tables9 questions · ~225 min
First Non-Repeating CharacterEasy
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Find the first non-repeating character in a string using frequency counting and a second pass in O(n) time.

Hash TablesStringsSearchingCloudsekBrightside HealthMcAfee
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4
Coding7 questions · ~175 min
Closures and Practical UseMedium
Practice
Recently asked

Use a Python closure with nonlocal state to process add and read operations on a running total.

CodingjavascriptabstractionRokuCCleverTapNtt Data Europe & Latam
Like Button ComponentMedium
Practice
Recently asked

Process Like button actions as a state machine while keeping its liked status and count consistent.

Codingclean codereactAADCI - KarnatakaAmazon Kuiper Commercial ServicesSupermicro
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5
debouncing4 questions · ~100 min
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6
Arrays5 questions · ~125 min
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7
More topics11 questions · ~275 min
Reverse String Without Built-insEasy
Practice
Recently asked

Reverse a string using basic iteration and swapping, without built-in reverse helpers.

Basic Algorithmsfunction implementationStringsCCypress GFISSagitec Solutions
Design Component HierarchyMedium
Practice

Convert flat UI component definitions into a nested hierarchy using parent references and a tree data structure.

reactabstractionData StructuresPersistent SystemsBBESTSECRET GroupCapital Technology Group
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