Executive Interview Preparation & Code WorkshopInteractive IDE
Practice high-frequency DSA algorithms, distributed systems, SQL, and STAR behavioral answers.
Curated Problem Tracks (5)
DSAEasy
Two Sum (Optimal One-Pass Hash Map)
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice.
DSAMedium
LRU Cache Design (Doubly Linked List + Hash Map)
Design a data structure that follows the constraints of a Least Recently Used (LRU) cache. Implement get(key) and put(key, value) in O(1) average time complexity.
SQLMedium
Second Highest Salary & Dense Ranking
Find the second highest distinct salary from the Employee table. If there is no second highest salary, return null.
System DesignMedium
Distributed Token Bucket Rate Limiter
Design a high-throughput distributed rate limiter protecting distributed microservices from abuse while allowing burst traffic up to a bucket capacity.
BehavioralEasy
Resolving Architectural Deadlocks (STAR Method)
Describe a time when you and another senior engineer disagreed on an architectural path forward. How did you resolve the conflict and what was the outcome?
Two Sum (Optimal One-Pass Hash Map)
DSA•Easy
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice.
Example Walkthrough:
Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Because nums[0] + nums[1] == 9, we return [0, 1].
Input: nums = [3,2,4], target = 6
Output: [1,2]
Time Complexity
O(n)
Space Complexity
O(n)
⚡Production Optimal Solution (PYTHON)
def twoSum(nums: list[int], target: int) -> list[int]:
seen = {}
for i, num in enumerate(nums):
diff = target - num
if diff in seen:
return [seen[diff], i]
seen[num] = i
return []