OpenAI mobile engineer interviews focus on iOS or Android platform knowledge, memory management, offline-first architecture, and mobile-specific system design.
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coding
Hard
Verified Question
#1
1. Count Machines In A Tree
Category: Tree coding problemYou are given a tree-structured network of machines where each node represents a machine. Machines can only communicate with their parent and...Input: String
Output: Computed result
coding
Medium
Verified Question
#2
2. Implement cd Command
Category: Algorithm coding problemImplement a simplified version of the Unix
cd command. Given a current directory path and a relative destination path, return the final absolute...Input: Given inputOutput: Computed result
coding
Medium
Verified Question
#3
3. Largest Subgrid
Category: Grid/matrix coding problemYou are given a 2D grid of non-negative integers and a maximum sum constraint. Find the largest size of a square sub-grid such that all...Input: 2D grid
Output: Integer
coding
Hard
Verified Question
#4
4. Memory Allocator
Category: Linked list coding problem# Memory Allocator Design a memory allocator that manages a contiguous block of memory. Implement
malloc and free operations with efficient...Input: Linked listOutput: Computed result
coding
Hard
Verified Question
#5
5. Toy Language Type Inference
Category: String coding problemImplement a type system for a toy programming language that supports primitives, tuples, and generics. Your task is to represent types and infer...Input: List
Output: Computed result
coding
Medium
Verified Question
#6
6. Virus Spread
Category: Grid/matrix coding problemSimulate the spread of a virus through a grid. Each cell can be in one of three states: healthy, infected, or immune. *This is similar to a leetcode...Input: 2D grid
Output: Integer
coding
Medium
Verified Question
#7
7. Bot-Enabled Messaging System
Category: String coding problemYou are building a chat system that supports human users and automated bots. Messages are added to a channel log and may trigger bot responses. The...Input: List
Output: Computed result
coding
Hard
Verified Question
#8
8. Connection Tracker
Category: Algorithm coding problemDesign a social network system that tracks follow relationships between users and preserves a full history through snapshots. The system allows...Input: List
Output: Computed result
coding
Medium
Verified Question
#9
9. GPU Credit Ledger
Category: String coding problemYou are designing a system to manage GPU credits. Each credit grant is valid during a specific time window. Events may arrive out of chronological...Input: String
Output: Computed result
coding
Medium
Verified Question
#10
10. GPU Credit Manager
Category: String coding problemYou are designing a system to manage GPU credits. Each credit grant is valid during a specific time window. Events may arrive out of chronological...Input: String
Output: Computed result
coding
Hard
Verified Question
#11
11. In-Memory SQL Engine
Category: String coding problemDesign an in-memory SQL database that supports creating tables, inserting rows with automatic type inference, and querying with filtering and sorting.Input: List
Output: Computed result
coding
Hard
Verified Question
#12
12. Persistent Key-Value Store
Category: Trie-based coding problemYou are designing a persistent key-value store that serializes its state to a binary storage medium. Native serialization (e.g., JSON, pickle,...Input: Array
Output: Computed result
coding
Hard
Verified Question
#13
13. Shard Rebalancer
Category: String coding problemYou are implementing a shard management system for a distributed key-value store. Each shard is identified by a string and covers a contiguous range...Input: String
Output: Computed result
coding
Hard
Verified Question
#14
14. IP Address Iterator
Category: String coding problemEvery device on the public internet is identified by an IPv4 address written in dotted-decimal notation as
"A.B.C.D", where each octet is an...Input: StringOutput: Computed result
coding
Medium
Verified Question
#15
15. Version Support Finder
Category: Binary search coding problemA software company maintains a sorted list of version strings in ascending chronological order. A critical feature was introduced in one version, and...Input: List
Output: Computed result
coding
Medium
Verified Question
#16
16. Monster Battle Simulator
Category: String coding problemSimulate a deterministic, turn-based battle between two ordered teams of monsters. Execute the fight step by step and produce a chronological battle...Input: List
Output: Computed result
coding
Medium
Verified Question
#17
17. Distributed Tree Messaging
Category: Tree coding problemYou are implementing a message-passing protocol for a distributed system organized as a rooted n-ary tree. Each node represents a machine and...Input: List
Output: Printed output
coding
Medium
binary search
#1
1. [OA] Binary Search — Find optimal model parameters for mobile inference
With the deployment of OpenAI models on mobile devices, it's essential to efficiently find the best-performing parameters from a given set of options. Binary search provides an efficient way to narrow down optimal configurations.
Given an array of integers
Input:
Output: 6
Explanation: The model with score 9 is the highest score at index 6.Example 2:
Input:
Output: 4Constraints:
-
-
Given an array of integers
models representing performance scores of models, write a method that returns the index of the highest performing model using binary search.Example 1:Input:
models = [3, 4, 5, 6, 7, 8, 9]Output: 6
Explanation: The model with score 9 is the highest score at index 6.Example 2:
Input:
models = [1, 2, 3, 4, 5]Output: 4Constraints:
-
1 <= models.length <= 10^5-
0 <= models[i] <= 10^4
coding
Hard
sliding window
#2
2. [OA] Sliding Window — Optimize the experience of streaming AI-generated content on mobile
OpenAI is focused on delivering seamless mobile experiences for users interacting with its generative AI tools. Effective management of data streams while accounting for mobile constraints is critical.
Given a string
Input: `s =
Given a string
s that consists of lowercase alphabets and an integer k, find the length of the longest substring that contains at most k distinct characters.Example 1:Input: `s =
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