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Coding & Algorithms Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 2071–2100 of 3276 results
- OpenAIMediumData ScientistIdentify Bugs in Python Script for User Assignment
This question evaluates a candidate's ability to detect bugs and data-quality risks in a Python script, testing competencies in code review, reproducible randomization, idempotency, logging, duplicate-exposure safeguards, and safe experiment-assignment logic.
Coding & AlgorithmsOnline Assessment - OpenAIMediumSoftware EngineerImplement A Contiguous Memory Allocator With Free-Block Coalescing
Design a fixed-size contiguous memory allocator supporting allocation and deallocation with immediate adjacent free-block coalescing.
Coding & AlgorithmsTechnical ScreenData StructuresIntervalsBinary Search - OpenAIEasySoftware EngineerImplement Chat Event Counter
This question evaluates data structures and algorithms competency, focusing on designing efficient in-memory counters and time-windowed event aggregation for (userId, chatId) pairs; it is categorized under Coding & Algorithms and has a practical implementation focus.
Coding & AlgorithmsTechnical Screen - OpenAIHardSoftware EngineerImplement Disease and Friend Snapshot Models
This question evaluates skills in graph-based modeling and temporal state simulation as well as the design and implementation of snapshot-capable directed graph data structures, covering competencies in propagation and state transitions (including immunity, recovery, and death), efficient snapshotting, querying, ranking, and diffing of follow relationships. It is commonly asked to assess algorithmic reasoning, correctness under edge cases, and complexity-aware implementation; the problem belongs to the Coding & Algorithms domain and tests both conceptual understanding of dynamic graph behavior and practical application-level implementation of data structures and immutable snapshots.
Coding & AlgorithmsOnsite - OpenAIMediumSoftware EngineerImplement GPU credit ledger
This question evaluates a candidate's ability to design efficient stateful systems and algorithmic data structures for tracking per-tenant resource balances, including handling idempotency, negative balance policies, concurrency, and persistence.
Coding & AlgorithmsTechnical Screen - OpenAIHardSoftware EngineerImplement IP Address Arithmetic
Implement parsing, binary representation, arithmetic offsets, and canonical formatting for both IPv4 and IPv6 addresses and CIDR subnets.
Coding & AlgorithmsOnsitebit-manipulationstring-parsingnetworking - OpenAIMediumSoftware EngineerImplement IPv4 and CIDR iterators
This problem tests your ability to manipulate IP address bit-representations and implement a custom iterator to traverse all addresses within a given CIDR block.
Coding & AlgorithmsTechnical ScreenBitwiseNetworkingIterator - OpenAIMediumSoftware EngineerImplement KV store and plan type conversions
This question evaluates proficiency in designing scalable, time-versioned key-value data structures and in graph-based shortest-path planning for costed type conversions, assessing algorithmic thinking, complexity analysis, and robustness under large-scale constraints in the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement KV store serialization
This question evaluates skills in binary serialization and deserialization, data encoding and layout, type tagging, endianness, checksumming, versioning for forward/backward compatibility, and algorithmic efficiency and space usage for an in-memory key-value store; it falls under the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement Social Follow Recommendations
This problem tests your ability to navigate a social graph to implement a recommendation system using set operations and frequency counting.
Coding & AlgorithmsTechnical ScreenGraphHash MapSorting - OpenAIMediumSoftware EngineerImplement Social Graph Snapshot Queries
This problem tests your ability to design a query-optimized representation for a directed graph, specifically focusing on efficient retrieval of multi-hop relationships and neighbor-based ranking.
Coding & AlgorithmsTechnical ScreenGraphsAdjacency ListData Structures - OpenAIMediumSoftware EngineerImplement Three Research Coding Tasks
This problem tests fundamental understanding of numerical stability in probability, memory-efficient buffering, and greedy combinatorial optimization.
Coding & AlgorithmsHR ScreenNumerical StabilityDynamic ProgrammingStreaming Algorithms - OpenAIMediumSoftware EngineerImplement Time-Aware GPU Credit Ledger
Design an in-memory credit ledger that tracks GPU compute grants with expiration timestamps, consumes credits greedily by earliest expiration, and supports atomic deductions.
Coding & AlgorithmsTechnical ScreenHeap / Priority QueueDesignGreedy - OpenAIHardSoftware EngineerImplement a Contiguous Memory Allocator with Primitive Lists
Simulate best-fit allocation across a contiguous address range using only primitive lists and scalar state. Support splitting, exact-pointer frees, double-free rejection, deterministic tie-breaking, and coalescing adjacent free blocks across up to 10,000 operations.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement a Distributed Rate Limiter
Implement a distributed token bucket rate limiter backed by a key-value store with optimistic concurrency control (CAS), handling clock skew, concurrent updates, and token replenishment.
Coding & AlgorithmsTechnical ScreenDistributed SystemsConcurrencyAlgorithms - OpenAIMediumSoftware EngineerImplement a GPU credit manager
This question evaluates understanding of concurrent resource management, advanced data structures for top-K and per-user queries, enforcement of caps and expirations, and algorithmic complexity guarantees while maintaining atomicity under concurrent operations.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement a memory allocator with malloc/free
This question evaluates understanding of memory allocator concepts including malloc/free semantics, contiguous allocation, fragmentation handling, coalescing of adjacent free blocks, pointer validation, and data-structure choices for efficient allocation.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement a serializable key-value store
This question evaluates competency in implementing robust serialization and in-memory data structures, covering binary format design, handling arbitrary bytes and Unicode, correctness across edge cases (empty state, large keys/values, overwrites, deletions), input validation and failure recovery, complexity analysis, and unit testing.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement an IPv4 Iterator
This problem tests your ability to handle IPv4 address arithmetic, bitwise operations, and the implementation of a stateful iterator that supports bidirectional traversal and range generation from CIDR notation.
Coding & AlgorithmsOnsiteBit ManipulationIterator PatternNetworking - OpenAIMediumSoftware EngineerImplement an IPv4 Range Iterator
This problem tests your ability to manipulate 32-bit integers, understand bitwise operations, and implement a custom iterator for a contiguous range of IP addresses.
Coding & AlgorithmsTechnical ScreenBit ManipulationNetworkingIterator - OpenAIMediumSoftware EngineerImplement an expiring GPU credits ledger
This question evaluates understanding of time-based resource accounting, design of data structures for expiring balances, atomic update semantics for concurrent operations, and algorithmic time/space complexity within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - OpenAIHardSoftware EngineerImplement an in-memory SQL-like table
This question evaluates implementation skills for an in-memory SQL-like table, focusing on data modeling with nested key-value structures, string handling, efficient lookups, and lexicographic sorting with tie-breaking.
Coding & AlgorithmsOnsite - OpenAIMediumSoftware EngineerImplement delimiter-free string codec
This question evaluates a candidate's ability to design reversible string encodings that handle arbitrary characters and edge cases, testing competency in string manipulation, data serialization, and robustness.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement expiring credit ledger
This question evaluates the ability to design efficient time-based data structures and algorithms for managing expiring credits with ordering and tie-breaking rules, testing competencies in event ordering, interval management, and retroactive update handling; it is in the Coding & Algorithms domain and emphasizes practical application of algorithmic and data-structure reasoning. It is commonly asked to verify correctness under out-of-order inserts and queries, to assess performance and complexity analysis for add/charge/get operations, and to require clear specification of time and space complexity for the proposed approach.
Coding & AlgorithmsTechnical Screen - OpenAIHardSoftware EngineerImplement follow graph with snapshots
This problem tests your ability to design a versioned, immutable, or persistent data structure that supports efficient graph modifications and point-in-time snapshot queries.
Coding & AlgorithmsTechnical ScreenPersistent Data StructuresGraphsVersion Control - OpenAIMediumSoftware EngineerImplement follow graph with snapshots and recommendations
This question evaluates design and implementation skills for mutable graph data structures with point-in-time snapshotting and recommendation ranking, testing knowledge of data structures, versioning, graph traversal, and algorithmic time/space complexity analysis.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement in-memory DB querying
This question evaluates a candidate's competency in data structures, algorithms, and systems-level thinking for implementing query processing in an in-memory database, including projection, predicate filtering, ordering, and index design.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement in-memory KV store with serialization
This question evaluates skills in designing and implementing an in-memory key-value store with serialization, testing data structure design, API design (set/get/serialize/deserialize), serialization format selection, type fidelity for common Python types, and robust error handling.
Coding & AlgorithmsTechnical Screen - OpenAIHardMachine Learning EngineerImplement in-memory database insert and delete operations
This question evaluates understanding of data structures and algorithmic complexity in the context of designing a key-value in-memory database, and it falls under the Coding & Algorithms domain for a Machine Learning Engineer role while focusing on practical implementation skills.
Coding & AlgorithmsOnsite - OpenAIMediumSoftware EngineerImplement node messaging and path discovery
This question evaluates skills in distributed systems and algorithms, including reliable message-passing between adjacent nodes, graph traversal and path discovery, fault-tolerant protocol design, and message/time complexity analysis.
Coding & AlgorithmsTechnical Screen
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