Goldmann Sachs | Associate | Interview
Summary
I completed a Coderpad round that featured LeetCode 490 (The Maze) and a SuperDay round with a system‑design problem and another LeetCode problem (Frequency of the Most Frequent Element).
Full Experience
Coderpad Round: Leetocde 490. The Maze https://leetcode.com/problems/the-maze/description/
SuperDay Round 1:
Question 1: /* * Your team is building a high‑throughput notification service. Due to network retries and upstream glitches, the service often receives duplicate notification payloads within a short timeframe. To prevent spamming users, you need to design an in‑memory Deduplication Engine that filters out duplicate notifications. System Constraints & Requirements Deduplication Window: A notification is considered a duplicate if we have seen the exact same notification_id (a UUID string) within the last 10 minutes. Scale: The system processes approximately 10,000 notifications per second. Memory Limit: The solution must run in‑memory on a single application instance with strict memory limits. You cannot let memory grow indefinitely; expired IDs (older than 10 minutes) must be cleaned up efficiently. Latency: The check‑and‑insert operation must be extremely fast (ideally O(1) or O(log N)). */
Question 2: https://leetcode.com/problems/frequency-of-the-most-frequent-element/description/
// A = [1,3,5,7,8,9,10,15], K = 6 // A = [1,3,5,10,8,9,10,15], K = 3 // A = [1,3,5,10,10,9,10,15], K = 1 // A = [1,3,5,10,10,10,10,15], K = 0 // output = 4
Interview Questions (3)
The Maze
LeetCode problem "The Maze" (ID 490). The task is to determine whether a ball can stop at a destination in a maze by rolling until it hits a wall.
In‑Memory Deduplication Engine for Notification Service
Design an in‑memory deduplication engine that filters duplicate notification payloads. Requirements: • Duplicate defined by identical notification_id (UUID) seen within the last 10 minutes. • Process ~10,000 notifications per second. • Operate on a single application instance with strict memory limits; expired IDs must be cleaned efficiently. • Check‑and‑insert operation should be O(1) or O(log N).
Frequency of the Most Frequent Element
Given an integer array A and an integer K, you can increment any element of the array by 1 at most K times. Return the maximum possible frequency of any element after performing at most K increments. Example: A = [1,3,5,7,8,9,10,15], K = 6 → output = 4.