practice a little every day, paws crossed ♡
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 931–960 of 3640 results
- ConfluentMediumSoftware EngineerDesign an LRU Cache with a Constant-Time Average
Design a fixed-capacity LRU cache whose get, put, and current-value average operations all run in expected constant time. Reason through map and recency-list invariants, running-sum updates, replacement and eviction edge cases, numeric precision, overflow, and tests that catch aggregate or ordering bugs.
Software Engineering FundamentalsOnsite - ConfluentMediumSoftware EngineerDesign an RSS News Feed Service
This question evaluates a candidate's ability to design a scalable RSS news feed service, emphasizing system architecture, relational schema and API design, including database table and index planning, ingestion and serving paths, deduplication/idempotency, and feed generation trade-offs.
System DesignOnsite - ConfluentMediumData ScientistDetermine Tutorial Completion Rate by Variant in 7 Days
This question evaluates a candidate's competency in data manipulation and event-based analytics, focusing on skills such as joining user and event tables, aggregating event data, and computing cohort completion metrics by variant.
Data Manipulation (SQL/Python)Onsite - ConfluentMediumSoftware EngineerDocument Search: Exact Word Match, Non-Adjacent Phrase Match and AND/OR Queries
A progressive coding round that builds search over a collection of documents. It starts with exact whole-word lookup, extends to multi-word queries whose words need not be adjacent, and ends with words combined by AND and OR, testing inverted indexes, set operations and clarifying ambiguous query semantics.
Software Engineering FundamentalsOnsite - ConfluentMediumData ScientistEvaluate Metrics and Randomization for Onboarding Tutorial Change
Evaluate Metrics and Randomization for Onboarding Tutorial Change evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite - ConfluentMediumSoftware EngineerExplain Linux Command Execution, Filesystems, and Isolation
Explain what Linux does from shell parsing through process creation, exec, waiting, and exit status, then trace paths, permissions, file descriptors, directories, procfs, and network inspection. Compare containers and virtual machines through their actual isolation boundaries and operational trade-offs.
Software Engineering FundamentalsOnsite - ConfluentMediumSoftware EngineerImplement File Tail and Sensor Health
This problem tests your ability to efficiently read the end of a growing file using file pointers and to implement a sliding time-window check for sensor heartbeat events.
Coding & AlgorithmsOnsiteI/OHash MapStreaming - ConfluentMediumSoftware EngineerImplement Tail and Find Monster Cost
This question evaluates competency in efficient file I/O and streaming techniques for implementing tail, and in graph search and shortest-path algorithms with path reconstruction for computing minimum monster cost in a grid.
Coding & AlgorithmsOnsite - ConfluentMediumSoftware EngineerImplement tail -n for a Very Large File
Implement the core of tail -n for a seekable file that may be many gigabytes without scanning it all when the requested suffix is small. Work through backward block reads, chunk boundaries, trailing-newline semantics, bounded memory, binary-versus-text handling, safe decoding, and mutation assumptions.
Software Engineering FundamentalsOnsite - ConfluentMediumSoftware EngineerMachine Coding: Word Search and Ordered Phrase Search Across a List of Documents
A machine-coding exercise that asks you to build a search component over a list of text documents, first finding the documents that contain a given word and then those where a phrase's words appear in the same sequence. It tests tokenization choices, index design, and handling of repeated words and edge cases.
Software Engineering FundamentalsOnsite - ConfluentMediumSoftware EngineerMatch Argument Type Lists Against Function Signatures with Variadic Parameters
A coding problem about resolving function calls: given a library of function signatures, some variadic in their last parameter, return every function that accepts each queried list of argument types. It tests precise matching rules, indexing signatures for many queries and deterministic output ordering.
Coding & AlgorithmsOnsite - ConfluentMediumSoftware EngineerMotivation and Readiness for a Developer Productivity Role from a Customer-Facing Team
A hiring-manager values-alignment round for a developer productivity role: walk through your background, then address a stated wish for distributed-systems work and a career spent on customer-facing teams. It tests honest motivation, transferable skills and a credible ramp-up plan.
Behavioral & LeadershipOnsite - ConfluentMediumSoftware EngineerPick Budget Line Items That Net to an Exact Target
A staged algorithm discussion: decide whether some subset of budget line items nets to an exact target amount, first with only charges and then with refunds (negative amounts) mixed in, then produce one such subset, then every distinct subset, reasoning about dynamic programming, pruned backtracking, and why negative values change the problem.
Software Engineering FundamentalsOnsitedynamic-programmingbacktrackingsubset-sum - ConfluentMediumSoftware EngineerPick Numbers Summing to a Target: Existence With Negatives, One and All Solutions
A staged coding discussion about choosing integers from a list so that they add up to a target. It asks whether a solution exists with only positive numbers and then with mixed signs, for one solution and for every solution without duplicates, and for optimizations, testing dynamic programming, pruned backtracking and reasoning about negative numbers.
Software Engineering FundamentalsOnsite - ConfluentMediumSoftware EngineerSearch Words and Phrases in a Large Line-Oriented File
Design word and exact-phrase search over a line-oriented file that may be much larger than memory. Compare a streaming one-off scan with a persistent positional inverted index, defining tokenization, Unicode and punctuation behavior, file-version binding, updates, result locations, and resource trade-offs.
Software Engineering FundamentalsOnsite - ConfluentMediumSoftware EngineerSolve Signature, File, and Queue Problems
This multi-part prompt evaluates skills in function signature and type matching, resource-constrained file I/O and streaming for large files, and data-structure design for randomized queues including multiset equality, synchronization, and compact run-length encodings.
Coding & AlgorithmsOnsite - ConfluentMediumSoftware EngineerValidate and Complete a Partially Filled 9x9 Sudoku Board
A coding problem that checks a partially filled 9x9 Sudoku board and completes it when possible. Solutions must detect givens that already break the row, column or box rules, recognize boards with no valid completion, and return a canonical completed grid, testing constraint checking and search.
Coding & AlgorithmsOnsite - ConfluentMediumSoftware EngineerWhy Confluent, and a Deep Dive into a Project You Worked On
A values and behavioral round for a senior software engineer built around two questions: why you want to join Confluent, and an in-depth walkthrough of a project you worked on. It tests motivation grounded in specifics, ownership of technical decisions and the ability to defend trade-offs under probing.
Behavioral & LeadershipOnsite - CoreweaveMediumSoftware EngineerBuild an OAuth-based data migration client
This question evaluates proficiency in OAuth 2.0 client-credentials authentication, API integration and pagination, JSON data transformation and checksum-based data integrity, token lifecycle management, retries, and idempotency within the Software Engineering Fundamentals category.
Software Engineering FundamentalsOnsite - CoreweaveMediumSite Reliability EngineerDesign Batch Reboots for Machines
This question tests the ability to design a distributed system that orchestrates machine reboots while maintaining cluster capacity, service availability, and operational safety.
System DesignOnsiteOrchestrationDistributed SystemsReliability - CoreweaveMediumSoftware EngineerDesign Tree Operations with DFS and BFS
Implement and compare Breadth-First Search (BFS) and Depth-First Search (DFS) operations on an N-ary tree representing a hierarchical compute cluster.
Software Engineering FundamentalsOnsiteTreesBFSDFS - CoreweaveMediumSoftware EngineerDesign a Human Workflow Distribution System
Design a distributed workflow allocation platform that routes tasks to human operators, tracks execution state via leases, and ensures fair queueing and fault tolerance.
System DesignOnsitesystem-designdistributed-systemsqueueing - CoreweaveMediumSoftware EngineerDesign a Notification System for Bursty Writes of 1M per Second
System design question for a notification system that must absorb bursty traffic of about one million writes per second. It covers requirements and capacity estimates, a queue-buffered write path, why a log-structured store such as Cassandra writes quickly, channel delivery and deduplication.
System DesignOnsite - CoreweaveMediumSoftware EngineerDesign a Strongly Consistent, Fault-Tolerant Database for Fleet Validation Data
System design question about the database between an OS validation service that writes results and a fleet management service that reads them, with strong consistency required. It probes primary and replica failures, synchronous versus asynchronous replication, failover, two-phase commit and consensus.
System DesignOnsite - CoreweaveMediumSoftware EngineerDesign a Website Monitoring Service
Design a globally distributed synthetic website monitoring service that executes periodic health probes, mitigates false-positive alerts, and ingests high-volume time-series metrics.
System DesignOnsitesystem-designdistributed-systemsmonitoring - CoreweaveMediumSoftware EngineerImplement web data fetch and storage tool
This question evaluates proficiency in HTTP client communication with token-based authentication, parsing structured responses into data models, relational database interaction including handling duplicate records, configuration management, and robust error handling and testing.
Coding & AlgorithmsOnsite - CoreweaveMediumSoftware EngineerJustify Building an In-House System Instead of Adopting an Existing Solution
Hiring manager question asking why a team built a system in-house when existing industry solutions were available. It tests build-versus-buy reasoning about scale, cost and fit, honest accounting of ownership costs, and credible evidence of the candidate's own technical contribution.
Behavioral & LeadershipOnsite - CoreweaveMediumSite Reliability EngineerQuery Machines and Mark Them Offline
This problem tests the ability to interact with external APIs, handle asynchronous operations with retries, and implement conditional filtering based on system metadata.
Coding & AlgorithmsOnsiteAPIAutomationError Handling - CoreweaveMediumSoftware EngineerRepresent and Evaluate Boolean Predicate Expressions
Design an object-oriented or tree-based representation for boolean predicate expressions and implement an evaluation engine that supports logical operators, comparison operations, and short-circuit evaluation against attribute dictionaries.
Software Engineering FundamentalsOnsiteobject-oriented-designtreesrecursion - CoupangMediumSoftware EngineerAnagram Group Tracker with Add, Remove, and Largest-Group Queries: Read vs Write Trade-offs
Design an in-memory data structure that supports adding words, removing words, and querying the largest anagram group. Tests canonical key generation, dynamic maximum maintenance, and read-versus-write algorithmic trade-offs.
Software Engineering FundamentalsOnsitehash-tabledesignstrings
Confluent
Coreweave
Coupang