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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.
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Showing 3121–3150 of 4616 results
- OptiverEasyQuantitative ResearcherStone Pile Doubling Game: Can One Pile Be Emptied?
This question evaluates a candidate's algorithmic reasoning and discrete-mathematics skills, particularly understanding deterministic state transitions, invariants, and cycle detection in iterative processes.
Coding & AlgorithmsTechnical Screen - OptiverMediumSoftware EngineerThread-Safe Stock Inventory: Buy and Sell Without Overselling
This question evaluates understanding of concurrent programming, synchronization primitives, atomicity, and correctness of shared mutable state by requiring implementation of a thread-safe inventory that prevents overselling and preserves updates.
Coding & AlgorithmsTechnical Screen - OptiverEasyQuantitative ResearcherTrading Game: Expected-Value Betting, Kelly Sizing, and Arbitrage Under Time Pressure
This question evaluates quantitative probability reasoning, expected-value computation, risk-sizing (including Kelly-style sizing), arbitrage recognition, and market-making intuition within a live trading simulation.
Machine LearningTechnical Screen - OracleMediumSoftware EngineerApproximate a Square Root Across Values Above and Below One
This problem tests binary search on a continuous search space and the ability to handle numerical precision for numbers both greater than and less than one.
Coding & AlgorithmsTechnical ScreenBinary SearchMathNumerical Methods - OracleMediumSoftware EngineerCheck That a String of Three Bracket Types Is Properly Nested
Decide whether a string made of round, square and curly brackets is properly nested, meaning every closing bracket matches the most recently opened bracket of the same type and nothing is left open. Tests careful handling of nesting order, crossing pairs and unmatched brackets at either end.
Coding & AlgorithmsTechnical Screen - OracleMediumSoftware EngineerClassify Tree Nodes in SQL
Tests the ability to write conditional logic and subqueries/joins in SQL to classify hierarchical tree nodes into 'Root', 'Inner', or 'Leaf'.
Data Manipulation (SQL/Python)Technical ScreenSQLPostgreSQLTrees - OracleMediumData ScientistCount Closed Islands
This problem tests your ability to navigate a 2D grid using graph traversal algorithms like DFS or BFS while identifying connected components that do not touch the grid boundaries.
Coding & AlgorithmsTechnical ScreenDFSBFSGraph - OracleMediumData ScientistCount Interior Islands After Flooding
This question evaluates understanding of grid-based graph traversal and connected-component detection, focusing on flood-fill logic and the treatment of boundary-connected regions in a binary grid.
Coding & AlgorithmsTechnical Screen - OracleMediumSoftware EngineerCount anagram-based replacements per phrase
This question evaluates skills in string processing, anagram grouping, frequency mapping, and combinatorial counting to determine how many phrase variations arise from permissible replacements in the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - OracleEasyData ScientistCount closed islands in a grid
This problem tests your ability to navigate a 2D grid using graph traversal algorithms like DFS or BFS while handling specific boundary constraints to identify closed regions.
Coding & AlgorithmsTechnical ScreenDFSBFSMatrix - OracleMediumSoftware EngineerDecide Whether a Parenthesis String With Star Wildcards Can Be Balanced
Decide whether a string of parentheses and stars can become a balanced parenthesis string when each star may independently act as an opening parenthesis, a closing parenthesis or an empty string. Tests reasoning over many possible replacements at once and edge cases with unmatched parentheses near either end.
Coding & AlgorithmsTechnical Screen - OracleMediumSoftware EngineerDesign a Video Upload Service for 100 GB Files with Chunked, Resumable Uploads
A system design question about building a service that accepts video uploads of up to 100 GB. It covers moving very large files efficiently, splitting them into chunks, resuming interrupted uploads, choosing storage for bytes and metadata, and scaling to many concurrent uploads.
System DesignTechnical Screen - OracleEasySoftware EngineerDesign structure for first unique login user
This question evaluates a candidate's ability to design an efficient online data structure that maintains a stream of login events and supports constant-time updates and queries for the earliest user with exactly one login.
Coding & AlgorithmsTechnical Screen - OracleHardSoftware EngineerEvaluate Subjective and Nondeterministic Agent Outputs
Create an evaluation program for subjective, nondeterministic AI-agent outputs when direct user feedback is sparse. Cover stratified tasks, versioned rubrics, repeated sampling, calibrated human review, judge agreement and bias, uncertainty-aware comparisons, severe-failure gates, online signals, and rollback criteria.
ML System DesignTechnical Screen - OracleMediumData ScientistExplain Medical AI Data and Evaluation
This question tests the ability to design an end-to-end evaluation and data pipeline for a clinical conversational agent, emphasizing safety, bias mitigation, and rigorous validation in a high-stakes environment.
Machine LearningTechnical ScreenLLMRAGHealthcare AI - OracleMediumSoftware EngineerExplain What Motivates You at Work
This question assesses your self-awareness, professional values, and how your personal work style aligns with the challenges of a fast-paced software engineering environment.
Behavioral & LeadershipTechnical ScreenBehavioralSelf-AwarenessSoft Skills - OracleHardSoftware EngineerHow do you prioritize and handle failures?
This question evaluates prioritization, incident-response and failure-management competencies including stakeholder communication, customer-impact mitigation, and learning-from-failure within the Behavioral & Leadership category for software engineers, emphasizing practical, experience-based application rather than abstract theory.
Behavioral & LeadershipTechnical Screen - OracleHardSoftware EngineerImplement Queue Operations Using Two Stacks
Implement queue enqueue, dequeue, and peek operations using exactly two LIFO stacks. The challenge tests transfer invariants, output ordering, amortized O(1) reasoning, large operation sequences, empty input, and compliance with restrictions against queue-like shortcuts.
Coding & AlgorithmsTechnical Screen - OracleEasySoftware EngineerImplement a Paginated Medical-Record Filter Without Guessing an Ambiguous Rule
This problem tests your ability to handle ambiguous business logic through requirement clarification and implement a robust, paginated filtering system for sensitive data.
Software Engineering FundamentalsTechnical ScreenPaginationRequirementsData-Validation - OracleHardSoftware EngineerImplement in-memory data structures and booking API
This problem tests your ability to design a thread-safe, in-memory booking system using efficient data structures to handle temporal queries and capacity management.
Coding & AlgorithmsTechnical ScreenHash MapConcurrencyAPI Design - OracleMediumSoftware EngineerMaximum of Fixed-Window Minimums
Tests the ability to compute sliding-window minima in linear time using a monotonic deque and determine the maximum value among those minima.
Coding & AlgorithmsTechnical Screensliding-windowmonotonic-queuedeque - OracleMediumSoftware EngineerMove Forward When Requirements Are Ambiguous
This question assesses a candidate's ability to navigate project uncertainty by balancing proactive problem-solving with effective stakeholder communication.
Behavioral & LeadershipTechnical ScreenBehavioralCommunicationProject Management - OracleMediumSoftware EngineerRearrange an Integer Array into Its Next Lexicographic Arrangement
A coding problem that asks you to rearrange an integer array into the next lexicographically greater arrangement of its values, wrapping around to ascending order when the array is already the largest. It tests reasoning about lexicographic order, repeated values and complexity analysis.
Coding & AlgorithmsTechnical Screen - OracleMediumSoftware EngineerRepeatedly Delete Runs of k Adjacent Equal Characters from a String
Given a lowercase string and an integer k, repeatedly delete k adjacent equal characters, letting the remaining parts join and possibly form new runs, until no deletion is possible, then return what remains. It tests efficient simulation of cascading removals on strings of up to 100,000 characters.
Coding & AlgorithmsTechnical Screen - OracleMediumSoftware EngineerSum the Binary Numbers Spelled by Root-to-Leaf Paths in a 0/1 Tree
Given a binary tree of 0 and 1 bits in level-order form, return the sum of the binary numbers spelled by every root-to-leaf path, reading the root as the most significant bit. The problem tests tree traversal, carrying an accumulated value down each path, and parsing a level-order serialization correctly.
Coding & AlgorithmsTechnical Screen - OscarEasySoftware EngineerDesign a Stateful Outreach Campaign Engine
This problem tests the ability to design a resilient, stateful task scheduler capable of handling asynchronous external triggers (responses) and idempotent state transitions.
System DesignTechnical ScreenDistributed SystemsState MachinesScheduling - OscarEasySoftware EngineerFind Clients Outside Provider Coverage
This problem tests spatial data processing and efficient set operations to identify gaps in service coverage between clients and providers based on distance and specialty requirements.
Coding & AlgorithmsTechnical ScreenAlgorithmsSpatialSet Operations - OtherMediumData ScientistBuild SQL pivot with lookups and currency conversion
This question evaluates proficiency in data manipulation using SQL or SQL-like Python transforms, covering point-in-time currency conversion, temporal joins for FX lookups, joins to enrich product/customer metadata, aggregation and pivot-style reporting, ranking, and data-quality checks for missing FX.
Data Manipulation (SQL/Python)Technical Screen - OtherEasyData ScientistCheck if a numeric string is divisible by 8
Determine whether a very large non-negative integer given as a decimal string is divisible by 8 without converting the whole string to an integer. The key insight is that only the last three digits matter (since 1000 is a multiple of 8), giving an O(1) check; a streaming modular-remainder approach is the O(n) alternative.
Coding & AlgorithmsTechnical Screen - OtherMediumBackend EngineerCompare Strings With Deletions
This question evaluates string processing and algorithmic optimization skills, specifically handling simulated deletions (backspace behavior) and performing comparisons under a strict auxiliary space constraint.
Coding & AlgorithmsTechnical Screen
Optiver
Oracle