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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 1021–1050 of 3640 results
- DatabricksMediumSoftware EngineerDesign an efficient Tic-Tac-Toe engine
This question evaluates a candidate's understanding of efficient algorithm design and minimal state management for a Tic-Tac-Toe engine on an n x n board, including constraints such as O(1) time per move and O(n) space.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerDesign an n x n Tic-Tac-Toe Game
This problem tests your ability to design an efficient class to manage game state, focusing on constant-time win condition checking using auxiliary data structures.
Coding & AlgorithmsOnsiteObject-Oriented DesignData StructuresOptimization - DatabricksMediumSoftware EngineerDesign bookstore and chat messaging systems
This question tests the ability to design two distinct systems: a reliable transactional e-commerce inventory service and a low-latency real-time chat application, focusing on appropriate database choices and communication protocols.
System DesignOnsiteDistributed SystemsDatabasesReal-time - DatabricksMediumMachine Learning EngineerDetect Harmful Content in LLM Prompts and Responses
Design a machine learning system that detects harmful content in prompts sent to, and responses produced by, a large language model. Tests policy-driven framing, labeling and adversarial data, layered classifiers under latency limits, per-category evaluation, streaming checks and monitoring.
ML System DesignOnsite - DatabricksMediumSoftware EngineerDetect a K-in-a-Row Win on a Rectangular Board
Implement an efficient win-detection function that checks whether a newly placed token forms at least k consecutive matching tokens along any linear axis on a rectangular grid.
Coding & AlgorithmsOnsiteArraysMatrixGame Theory - DatabricksHardSoftware EngineerDiscuss Motivation, Feedback, and Technical Disagreement
This interview module evaluates engineering motivation, individual technical ownership, constructive receipt of critical feedback, and principled conflict resolution during technical disagreements.
Behavioral & LeadershipOnsiteBehavioralLeadershipConflict Resolution - DatabricksMediumSoftware EngineerEarliest Substring That Is a Rearrangement of a Pattern
Find the starting index of the first substring of a text that is a rearrangement of a given pattern, or report that none exists. Tests fixed-length sliding windows, character-frequency bookkeeping and linear-time scanning of long strings with an early exit.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerExplain storing files to disk with concurrency
This question tests your understanding of OS-level file I/O operations, the risks of concurrent writes to the same file descriptor, and how to implement robust thread-safe mechanisms to maintain file integrity.
Software Engineering FundamentalsOnsiteConcurrencyFile I/OOS Fundamentals - DatabricksMediumSoftware EngineerFastest Single-Mode Commute on a Grid with Per-Step Time and Cost
Given a city grid with a start, a destination and cells usable by only one of four commute modes, choose the mode whose trip takes the least total time, breaking ties by lower total cost. Tests shortest-path search on grids, per-mode reachability and precise tie-breaking.
Coding & AlgorithmsOnsite - DatabricksHardSoftware EngineerFind all anagram start indices
This problem tests your ability to efficiently detect pattern matches within a stream or string using a sliding window technique and frequency mapping.
Coding & AlgorithmsOnsiteStringsSliding WindowHash Map - DatabricksMediumSoftware EngineerFirst-Match CIDR Firewall: Status of an IP Address or a Whole CIDR Block
Implement an ordered first-match IPv4 firewall that returns ALLOW or DENY for an address, then extend it so the target can be a whole CIDR block that is allowed only if every address inside it is. Tests bit-level prefix matching and reasoning about address ranges at scale.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerGeneralized m x n Tic-Tac-Toe with a k-in-a-Row Win Check
Implement tic-tac-toe on an m by n board where a player wins with k consecutive marks in a row, column or either diagonal, returning the winner after each move. Tests incremental win detection that avoids rescanning the board, plus careful handling of edges and both diagonal directions.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerImplement Column Pruning and Filter Pushdown on a Query Plan Tree
Given a SQL query represented as a tree of scan, filter, project and join nodes, write runnable rewrites that prune unused columns from every scan and push filter conditions down toward the tables. Tests query-optimizer fundamentals, recursive tree rewriting and preserving query results.
Software Engineering FundamentalsOnsite - DatabricksHardSoftware EngineerImplement Generalized Tic-Tac-Toe
Design and implement a generalized m x n Tic-Tac-Toe game supporting an arbitrary winning streak length k. Tests grid simulation, efficient line checking around the latest move, and handling boundary conditions.
Coding & AlgorithmsOnsiteDesignArrayMatrix - DatabricksMediumMachine Learning EngineerImplement Gradient Descent Regression
This problem tests your understanding of linear regression by requiring the implementation of a gradient descent optimizer from scratch to minimize the Mean Squared Error loss.
Machine LearningOnsiteLinear RegressionGradient DescentOptimization - DatabricksMediumMachine Learning EngineerImplement Linear Regression Gradient Descent
This question tests the ability to implement batch gradient descent for simple linear regression from scratch, requiring the derivation of gradients for weights and bias, and understanding how to optimize convergence.
Machine LearningOnsiteGradient DescentLinear RegressionOptimization - DatabricksMediumFrontend EngineerImplement Resilient Autocomplete Data Fetching
Implement resilient autocomplete fetching with a quiet period, bounded retries, newest-query precedence, and reuse of recent results. Cover empty input, out-of-order responses, cancellation during waits and requests, error classification, freshness and capacity policies, unmount safety, accessibility, shared requests, and responsive ranking.
Software Engineering FundamentalsOnsite - DatabricksMediumMachine Learning EngineerImplement Simple Linear Regression with Gradient Descent from Scratch
Write simple linear regression trained with gradient descent from scratch, choosing the loss, learning rate and stopping rule yourself. Tests deriving the gradients correctly, writing a runnable training loop, understanding feature scaling and convergence, and verifying results against a closed-form fit.
Machine LearningOnsite - DatabricksMediumSoftware EngineerImplement a Concurrent Buffered File Logger
Design and implement a thread-safe, buffered logger that aggregates concurrent writes across multiple threads and flushes them to disk efficiently with documented ordering guarantees.
Software Engineering FundamentalsOnsiteConcurrencyMultithreadingObject-Oriented Design - DatabricksHardSoftware EngineerImplement a Tic-Tac-Toe game API
This problem tests your ability to design a state-tracking system for an n x n Tic-Tac-Toe board that allows for constant-time move validation and win detection.
Coding & AlgorithmsOnsiteAlgorithmsData StructuresOptimization - DatabricksMediumSoftware EngineerImplement a rate-limited hit counter
This question evaluates a candidate's understanding of designing efficient time-windowed data structures and algorithmic analysis, including space-time trade-offs and amortized complexity.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerImplement a snapshotable set with iterators
This question evaluates understanding of persistent/versioned data structures, iterator semantics, concurrency control, and complexity-aware design for mutable sets, and is categorized under Coding & Algorithms.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerImplement lazy array and KV store
This problem tests your ability to implement lazy computation using function composition and design a stateful data structure with metadata tracking.
Coding & AlgorithmsOnsiteFunctional ProgrammingData StructuresAPI Design - DatabricksMediumSoftware EngineerImplement run-length encoding and decoding
This question evaluates proficiency in string manipulation and encoding algorithms, specifically run-length encoding and decoding, along with attention to edge cases such as empty inputs and single-character runs and correct handling of repetition counts.
Coding & AlgorithmsOnsite - DatabricksHardSoftware EngineerImplement streaming RLE and bit-packed codec
This question evaluates understanding of data compression algorithms, bit-level manipulation, two's‑complement integer representation, streaming algorithm design, and encoder/decoder state management for 32-bit signed integers.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerInteger Set with O(1) Snapshot Iterators Unaffected by Later Changes
Design a set of integers with amortized constant-time add and remove whose iterators capture the exact contents at creation time without copying, stay independent of later changes and of each other, and fit in linear total space. Also compares a shared history log with per-key logs.
Software Engineering FundamentalsOnsite - DatabricksMediumSoftware EngineerLowest-Price Book Aggregator Fanning Out to Hundreds of Async Bookstores
Design a middleman service that takes an ISBN, bid price and payment method, queries several hundred asynchronous bookstores for the lowest price, and then orders, returns the price or reports no stock. Deep dives cover partial results and circuit breakers, caching against thundering herds, and order-and-charge consistency.
System DesignOnsite - DatabricksMediumSoftware EngineerPartition a Target String by Source Substrings
Determine the minimum number of contiguous substrings from a source string required to reconstruct a target string.
Coding & AlgorithmsOnsitestringsgreedysuffix-automaton - DatabricksMediumSoftware EngineerPath Between Two Preorder-Numbered Nodes of an Implicit Fibonacci Tree
Given the order of a recursively defined Fibonacci tree and two nodes labeled by preorder number, return the path between them without building a tree that can hold trillions of nodes. Tests recursive subtree-size reasoning, implicit tree navigation and 64-bit index arithmetic.
Coding & AlgorithmsOnsite - DatabricksHardSoftware EngineerPresent a Technical Project Under Active Follow-Up
This question assesses a candidate's ability to articulate the architecture, personal impact, and technical decision-making process behind a complex engineering project while navigating intense scrutiny.
Behavioral & LeadershipOnsiteSystem DesignLeadershipTechnical Communication
Databricks