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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.
- 9403
- Questions
- 546
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- 11
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- 8
- Languages
Showing 2731–2760 of 9403 results
- 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 - DatabricksHardSoftware EngineerEvaluate ACL rules for IP and CIDR
This problem tests your ability to manipulate binary representations of IP addresses and perform efficient prefix matching using CIDR notation, requiring careful bitwise arithmetic and efficient lookup structures.
Coding & AlgorithmsTechnical ScreenBit ManipulationTrieNetworking - DatabricksHardData ScientistExplain Linear Regression Assumptions
This question tests the candidate's mastery of the Gauss-Markov theorem and the consequences of violating Ordinary Least Squares (OLS) assumptions in real-world data science workflows.
Statistics & MathTechnical ScreenStatisticsRegressionOLS - DatabricksMediumData ScientistExplain Linear Regression Feature Transformation Equivalence
This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Explain Linear Regression Feature Transformation Equivalence states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningOnline Assessment - DatabricksMediumSoftware EngineerExplain Your Motivation, Fit, and Company Understanding
Prepare a coherent recruiter-screen narrative for a senior forward-deployed engineering role, covering motivation, evidence of fit, and verified company understanding. Use authentic examples of technical depth, delivery through ambiguity, customer communication, measured outcomes, honest gaps, uncertainty, and questions that test mutual fit.
Behavioral & LeadershipHR Screen - 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 - DatabricksMediumBackend EngineerFind First Anagram Occurrence
This question evaluates proficiency in string processing, character-frequency analysis, and efficient substring search techniques, measuring competency in algorithmic reasoning and implementation for pattern matching.
Coding & AlgorithmsTechnical Screen - DatabricksHardSoftware EngineerFind Path Between Fibonacci Tree Nodes
This problem tests your ability to map nodes in a recursively defined tree structure without materializing the tree, requiring an understanding of Fibonacci sequences and path-finding algorithms in binary trees.
Coding & AlgorithmsTechnical ScreenTreesRecursionMath - DatabricksHardData ScientistFind Top-5 Similar Rows
This question tests the ability to implement a pairwise similarity comparison between rows using a custom distance metric while handling missing data and ranking results.
Data Manipulation (SQL/Python)Technical ScreenPandasSimilarityData Manipulation - 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 EngineerFind first CIDR block covering IP
This question evaluates a candidate's understanding of IPv4 and CIDR notation, ability to perform prefix-based address containment checks using bitwise reasoning, and competence in parsing and efficient lookup across many ranges.
Coding & AlgorithmsTechnical Screen - DatabricksMediumSoftware EngineerFind k customers with least revenue
This question evaluates a candidate's ability to aggregate per-customer revenue from event streams and perform selection on aggregated totals, testing knowledge of data aggregation, selection algorithms, and efficient use of data structures.
Coding & AlgorithmsTechnical Screen - DatabricksHardSoftware EngineerFind path between nodes in Fibonacci tree
This problem tests your ability to navigate implicit tree structures defined by recurrence relations and your proficiency in pathfinding within large graphs without materializing them.
Coding & AlgorithmsTechnical ScreenTreesRecursionFibonacci - DatabricksHardSoftware EngineerFind shortest path in a Fibonacci-ordered tree
This question evaluates understanding of recursive binary tree structures, preorder indexing, Fibonacci-like size relations, and arithmetic-based navigation for computing paths in an implicitly defined tree.
Coding & AlgorithmsTechnical Screen - DatabricksEasyData ScientistFind top-5 most similar rows across datasets
This question evaluates understanding and implementation of similarity/distance metrics (e.g., MSE), data preprocessing issues such as handling NULLs and feature scaling, and the ability to perform efficient cross-dataset comparisons and top-k ranking.
Data Manipulation (SQL/Python)Technical Screen - 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 EngineerForward Deployed Engineer Screen: Role Fit, Client Work and Databricks Projects
Practice answers for a short recruiter phone screen for a Forward Deployed Engineer role at Databricks. It covers preferred location, understanding of the role, an experience walkthrough, client-facing work, data engineering tools built, a project delivered on Databricks, and programming languages, testing concise and honest communication.
Behavioral & LeadershipHR Screen - 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 - DatabricksHardSoftware EngineerIdentify and handle race conditions
This question evaluates understanding of concurrency, race conditions, synchronization mechanisms, and performance trade-offs in designing thread-safe in-memory data structures like key-value stores and hit counters.
System DesignTechnical Screen - DatabricksMediumSoftware EngineerImplement CIDR firewall matcher
This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Implement CIDR firewall matcher states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - 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 Snapshot Iterator Without Order Guarantees
This question evaluates data-structure design and iterator semantics—specifically snapshot iteration over a mutable, set-like collection without order guarantees—and tests skills in implementing mutation-isolated iteration and analyzing time and space complexity; it belongs to the Coding & Algorithms domain and emphasizes practical implementation.
Coding & AlgorithmsTechnical Screen - 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 Snapshot Set Iterator
This question evaluates understanding of set data structures, iterator and snapshot semantics, and the ability to reason about time and space complexity when providing stable views over mutable collections.
Coding & AlgorithmsTechnical Screen
Databricks