Interview Prep

Real questions for real interviews. C#, Python, Go, SQL. Junior → System Design.

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C# / .NET

Junior

Find all duplicate integers in an array in O(n) time
Coding Frequent C# arrays HashSet
Two Sum — return indices of two numbers that add up to a target
Coding Very frequent C# arrays Dictionary
Check if a string is a palindrome (ignoring case and non-alphanumeric characters)
Coding Frequent C# two pointers strings

Python

Junior

Write a generator function that yields Fibonacci numbers indefinitely
Coding Frequent Python generators yield
Two Sum in Python — return indices of two numbers that add to a target
Coding Very frequent Python Two Sum hash map

Go

Junior

Write a Go function that fans out HTTP requests using goroutines and collects results via channels
Coding Frequent Go goroutines channels
Two Sum in Go — return indices of two numbers that add up to a target
Coding Frequent Go arrays maps

SQL

Junior

Write a query to find all employees who earn more than the average salary.
Coding Very frequent SQL subquery aggregation