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Interview questions by company and topic | SysRound

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95 questions

Showing 1–25

CodingMediumLeetCode 146
LRU Cache
Implement an LRUCache that supports O(1) average-time get(key) returning the value or -1 and put(key, value) which inserts or updates a key and, if capacity…
Companies: Adobe, Amazon, Anthropic, Apple +29
Data Structure Design · Design · Doubly-Linked List · Hash Table
Last reported Oct 2026
Open workspace
Practical engineeringHard
Rectangle grid with IDs: coverage counts, replace and delete, O(1) queries, batch undo
Companies: OpenAI
Data Structure Design
Last reported Oct 2026
Open workspace
Practical engineeringHard
Chat event aggregator: sliding-window message counts and active chats per user

Page 1 of 4

Companies: OpenAI

Data Structure Design · Stacks & Queues

Last reported Oct 2026

Practical engineeringHard

Fault-Tolerant Task Queue with Retries, a Dead-Letter Queue and Task Dependencies

Companies: OpenAI

Data Structure Design · Graphs

Last reported Oct 2026

Practical engineeringHard

Implement a GPU credit ledger: grant credits, charge usage, report the balance

Companies: OpenAI

Data Structure Design

Last reported Oct 2026

Practical engineeringHard

Rectangle board: add rectangles, count those covering a point, and undo

Companies: OpenAI

Data Structure Design

Last reported Oct 2026

Practical engineeringMedium

Sliding-Window Chat Analytics: Recent Counts, Live Sessions, Out-of-Order Events

Companies: OpenAI

Data Structure Design · Stacks & Queues

Last reported Oct 2026

Practical engineeringHard

Fault-Tolerant Task Queue with Retry Cooldowns, a Dead-Letter Queue and Dependencies

Companies: OpenAI

Data Structure Design · Graphs

Last reported Oct 2026

Practical engineeringMedium

Social Graph with Follow/Unfollow, Snapshots, History Queries and Recommendations

Companies: OpenAI

Data Structure Design · Graphs

Last reported Oct 2026

System designMedium

Check-and-Insert for a Million User IDs: Balancing Latency, Memory and Accuracy

Companies: Mercor

Data Structure Design · System Design · System Design Fundamentals

Last reported Oct 2026

Practical engineeringHard

Implement malloc and free over Fixed Memory, Then Make Both Logarithmic

Companies: OpenAI

Data Structure Design · Memory Management

Last reported Oct 2026

Practical engineeringMedium

Implement a fault-tolerant work queue that never loses tasks when workers fail

Companies: OpenAI

Concurrency · Data Structure Design

Last reported Oct 2026

CodingMedium

IPv4 Address Iterator

Implement an iterator that traverses IPv4 addresses starting from a given address, supporting forward iteration, reverse iteration, and CIDR block iteration.

Companies: Anthropic, OpenAI

Data Structure Design · Networking

Last reported Oct 2026

Practical engineeringMedium

Implement a GPU credit ledger with expiring grants and out-of-order operations

Companies: OpenAI

Data Structure Design · Heaps & Priority Queues

Last reported Sep 2026

Practical engineeringMedium

Spreadsheet engine with setCell/getCell, cell references, and cycle detection

Companies: OpenAI

Data Structure Design · Graphs

Last reported Sep 2026

Practical engineeringMedium

GPU Credit Ledger: Spend Earliest-Expiring Credits First, Stop on Overdraft

Companies: OpenAI

Data Structure Design · Heaps & Priority Queues

Last reported Sep 2026

Practical engineeringHard

Count Events in a Trailing 15-Minute Window with a Fixed-Size Ring Buffer

Companies: OpenAI

Data Structure Design

Last reported Sep 2026

Practical engineeringHard

Follow Graph with Cheap Snapshots and Top-K Follow Recommendations

Companies: OpenAI

Data Structure Design · Graphs

Last reported Sep 2026

Practical engineeringHard

GPU Credit Ledger with Expiring Grants, Out-of-Order Operations and Fast Balances

Companies: OpenAI

Data Structure Design · Heaps & Priority Queues

Last reported Sep 2026

CodingHard

Leftmost-Fit Memory Allocator: Allocate Consecutive Units and Free by Owner

Companies: OpenAI

Data Structure Design · Trees

Last reported Sep 2026

Practical engineeringHard

Text Editor in Four Stages: Buffer, Undo/Redo, Trie Autocomplete, Collaborative OT

Companies: OpenAI

Data Structure Design · Real-Time Systems

Last reported Sep 2026

Practical engineeringMedium

At-Least-Once Job Queue with Timeouts, Retries, a Dead-Letter Queue and Dependencies

Companies: OpenAI

Data Structure Design · Job Scheduling & Workflows

Last reported Sep 2026

Practical engineeringMedium

Fix a Buggy LRU Cache, Then Make It Durable with a Write-Ahead Log

Companies: Anthropic

Data Structure Design · Debugging

Last reported Sep 2026

Practical engineeringMedium

Expiring GPU Credit Ledger with Out-of-Order Events and Point-in-Time Balance

Companies: OpenAI

Data Structure Design · Heaps & Priority Queues

Last reported Sep 2026

System designMedium

Design Food-Delivery Proximity Search for Restaurants Within 10 km

Companies: Microsoft

Data Structure Design · System Design

Last reported Sep 2026