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Top 50 QA Engineer Interview Questions

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

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1
CodingStart here. 25 questions · ~563 min
Reverse a StringEasy
Practice
Recently asked

Reverse a string using a two-pointer swap approach and explain the trade-off between in-place and copied results.

RecursionArraysStringsBroadridge Financial SolutionsDDXCCNA
Palindrome Function ImplementationEasy
Practice
Recently asked

Determine whether a string reads the same forward and backward using a two-pointer scan.

RecursionStringsTwo PointersInformaticaENGIEDDelivery Hero India
First Non-Repeating CharacterMedium
Practice
Recently asked

Find the first non-repeating character in a string using frequency counting and a second pass in O(n) time.

Hash TablesStringsSearchingCogniteWalgreens Boots AllianceForeFlight
Two Sum with TargetEasy
Practice
Recently asked

Use a hash map to find two array elements that sum to a target in O(n) time.

Hash TablesArraysStringsEsystemsBungalowSide
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2
SQL & Data Manipulation25 questions · ~563 min
Second Highest Without AggregatesMedium
Practice
Recently asked

Find the second highest salary in each department without using aggregate functions.

SubqueriesRankingSelf-JoinsMicron Memory Malaysia Sdn BhdInformaticaExusia
Second Highest Trader SalaryEasy
Practice
Recently asked

Find the second highest distinct salary from a single table using basic PostgreSQL ordering and limiting.

SubqueriesRankingSortingAntraWNSState Street
SQL Duplicate DetectionMedium
Practice
Recently asked

Find duplicate customer profiles by grouping on identifying fields and returning only repeated records.

Group ByHavingAggregationsUniversity of Southern CaliforniaCircle Internet FinancialRevature
Second Highest Salary at NovaTechEasy
Practice
Recently asked

Find the second highest distinct employee salary from a single table, returning NULL if it does not exist.

SubqueriesRankingAggregationsBest BuyAmtex SystemsC3 AI
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