MongoDB Software Engineer Onsite Coding Questions
11+ questions from real MongoDB Software Engineer Onsite Coding rounds, reported by candidates who interviewed there.
What does the MongoDB Onsite Coding round test?
The MongoDB onsite coding round is the core technical evaluation. Software Engineer candidates typically see 2-3 algorithm and data structure problems. Problems range from medium to hard difficulty, and interviewers evaluate both correctness and code quality.
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MongoDB Software Engineer Onsite Coding Questions
LeetCode #208: Implement Trie (Prefix Tree). Difficulty: Medium. Topics: Hash Table, String, Design, Trie. Asked at MongoDB in the last 6 months.
#1146 Snapshot Array
LeetCode #1146: Snapshot Array. Difficulty: Medium. Topics: Array, Hash Table, Binary Search, Design. Asked at MongoDB in the last 6 months.
#146 LRU Cache
LeetCode #146: LRU Cache. Difficulty: Medium. Topics: Hash Table, Linked List, Design, Doubly-Linked List. Asked at MongoDB in the last 6 months.
LeetCode #139: Word Break. Difficulty: Medium. Topics: Array, Hash Table, String, Dynamic Programming, Trie, Memoization. Asked at MongoDB in the last 6 months.
LeetCode #349: Intersection of Two Arrays. Difficulty: Easy. Topics: Array, Hash Table, Two Pointers, Binary Search, Sorting. Asked at MongoDB in the last 6 months.
#23 Merge k Sorted Lists
LeetCode #23: Merge k Sorted Lists. Difficulty: Hard. Topics: Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort. Asked at MongoDB in the last 6 months.
MongoDB SWE Onsite - Hash Table
## Problem Design and implement a hash table with efficient insert, lookup, and delete operations, likely discussing collision resolution strategies. ## Likely LeetCode equivalent LeetCode 706 - Design HashMap. ## Tags hash_table,design,swe
## Problem Given an array of integers, return the array of their squares sorted in non-decreasing order. ## Likely LeetCode equivalent LeetCode 977 - Squares of a Sorted Array. ## Tags sorting,two_pointers,arrays,swe
MongoDB SWE Onsite - Iterators
## Problem Implement a custom iterator or iterator combinator (e.g., peeking iterator, zip, or flatten), requiring understanding of the iterator design pattern. ## Likely LeetCode equivalent LeetCode 284 - Peeking Iterator. ## Tags design,iterator,ood,swe
MongoDB SWE Onsite - Random Dice Roll
## Problem Simulate rolling one or more dice, computing the probability distribution of outcomes or implementing a weighted random generator. ## Likely LeetCode equivalent LeetCode 528 - Random Pick with Weight. ## Tags probability,simulation,math,swe
## Problem Implement a simplified regex matcher supporting characters like '.', '*', or specific character classes against an input string. ## Likely LeetCode equivalent LeetCode 10 - Regular Expression Matching. ## Tags strings,dynamic_programming,recursion,swe
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