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Backend Engineer 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 1–26 of 26 results
- AirwallexMediumBackend EngineerMaximum Triangle Path Sum, Overall and Through a Required Cell
Given an integer triangle where each step moves to one of the two adjacent cells in the next row, return the maximum top-to-bottom path sum and the maximum sum among paths forced through a given cell. Tests dynamic programming on a triangle and adapting it to a constrained follow-up.
Coding & AlgorithmsOther - Applied IntuitionHardBackend EngineerResolve Dependent Addition Equations
Implement an equation evaluator that computes the integer values of variables defined in terms of literals and other variables while detecting cycles and undefined references.
Coding & AlgorithmsTechnical ScreenGraphTopological SortDFS - ByteDanceHardBackend EngineerSolve Bracket Matching and Tree Width
This problem tests string manipulation and tree traversal techniques by requiring the validation of complex bracket sequences and the calculation of the maximum horizontal distance between nodes at the same level of a binary tree.
Coding & AlgorithmsHR ScreenStacksBFSTrees - ChimeMediumBackend EngineerSolve classic backend coding problems
This problem tests your ability to handle string manipulation, recursion with backtracking, and mapping logic by generating all valid word combinations from a numeric keypad sequence.
Coding & AlgorithmsTechnical ScreenBacktrackingRecursionStrings - CoinbaseMediumBackend EngineerImplement a Stateful Trading Order Manager
This problem tests your ability to design a stateful system using hash-based sharding, efficient indexing, and robust state machine transitions for high-frequency financial orders.
Coding & AlgorithmsOnsiteHash TablesSystem DesignState Machines - CourseraHardBackend EngineerImplement Popular and Ranked Voting
This question evaluates algorithmic implementation skills and understanding of voting systems, including aggregation of first-place preferences and the conceptual mechanics of elimination-based ranked-choice counting.
Coding & AlgorithmsTechnical Screen - 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 - HarveyMediumBackend EngineerImplement tag matcher and filesystem
This combined prompt evaluates string-processing and parsing skills for tag matching and design/implementation skills for an in-memory file system, measuring competencies in exact whole-word matching, case normalization, punctuation and duplicate handling, path parsing, hierarchical data structures, and file API behaviors.
Coding & AlgorithmsOnsite - InstacartMediumBackend EngineerFix the Broken Search Filter in a Book Catalog API
This problem tests your ability to sanitize inputs and implement robust filtering logic on a collection of structured objects using multiple criteria.
Coding & AlgorithmsOnline AssessmentFilteringStringsBackend - MetaMediumBackend EngineerSolve coding and AI-assisted tasks
This problem tests your ability to manipulate tree structures with parent pointers and verify path validity under specific movement constraints.
Coding & AlgorithmsOnsiteTreesData StructuresAlgorithms - New RelicMediumBackend EngineerCompress a String by Run-Length Counts, Keeping the Original When Not Shorter
Implement run-length string compression that replaces each run of repeated characters with the character and its count, returning the original string when the compressed form is not strictly shorter. Tests careful run handling, multi-digit counts, the tie rule, and complexity and edge-case discussion.
Coding & AlgorithmsOnsite - New RelicMediumBackend EngineerLongest Strictly Increasing Path in a Grid with Four-Directional Moves
Given an integer matrix, find the number of cells on the longest path whose values strictly increase, moving only up, down, left, or right with no diagonal steps and no wrap-around at the edges. Tests grid search and the ability to turn a working first solution into an efficient one.
Coding & AlgorithmsOnsite - NuroHardBackend EngineerImplement BFS and a Job Scheduler
Solve grid reveal with BFS and design a thread-safe periodic job scheduler. The solution covers Minesweeper-style expansion, queue processing, priority-queue scheduling, locks, worker pools, cancellation, duplicate prevention, long-running tasks, clock drift, and backpressure.
Coding & AlgorithmsOnsite - OpenAIMediumBackend EngineerConvert IPv4 Ranges to CIDR Blocks
This question evaluates understanding of IPv4 addressing, binary/bitwise manipulation, and the ability to summarize consecutive address ranges into minimal CIDR blocks, and belongs to the Coding & Algorithms domain for backend engineering roles.
Coding & AlgorithmsTechnical Screen - OpendoorHardBackend EngineerExecute a TTL Key-Value Store with Transactions
This problem tests the implementation of an in-memory key-value store supporting TTL expiration, atomic transactions with rollback capabilities, and logical time-based validation.
Coding & AlgorithmsTechnical ScreenHashMapsTransactionsTTL - OracleMediumBackend EngineerAdd One to an Integer Stored as Digits Without ArrayList
This problem tests array manipulation skills and the ability to handle carry-over logic in fixed-size numerical representations.
Coding & AlgorithmsOnsiteArraysMathAlgorithms - OracleMediumBackend EngineerFind the Best Profit from One Stock Trade
Tests array traversal, greedy state tracking, and achieving optimal O(n) time and O(1) space complexity for trade optimization.
Coding & AlgorithmsOnsiteArrayDynamic ProgrammingGreedy - OracleMediumBackend EngineerReturn the K Most Frequent Values with a Larger-Value Tie-Break
This problem tests proficiency with hash maps for frequency counting and custom sorting logic using priority queues or sorting algorithms.
Coding & AlgorithmsOnsiteHash MapSortingPriority Queue - OracleMediumBackend EngineerSplit a String into Exactly Three Palindromes
Tests string partitioning, palindrome verification, and algorithmic optimization using dynamic programming or two pointers.
Coding & AlgorithmsOnsiteStringDynamic ProgrammingTwo Pointers - 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 - RilletMediumBackend EngineerDistribute Annual Revenue Across Twelve Months
This problem tests logic, integer arithmetic, and edge-case handling by requiring the distribution of a total sum into equal parts while managing remainders without using floating-point numbers.
Coding & AlgorithmsTechnical ScreenAlgorithmsInteger ArithmeticData Manipulation - RobinhoodMediumBackend EngineerCount and Rank Words in a Paragraph
This problem tests string manipulation, hash map usage for frequency counting, and custom sorting logic for deterministic ordering.
Coding & AlgorithmsTechnical ScreenStringsHash MapSorting - SpotifyMediumBackend EngineerLongest Contiguous Stretch of Distinct Characters in a String
A Spotify backend technical-screen coding problem: given a string, find the length of the longest contiguous substring in which no character repeats. It tests careful string scanning, linear-time reasoning, and edge cases such as case sensitivity, ties and empty input.
Coding & AlgorithmsTechnical Screen - TargetMediumBackend EngineerFind the Closest Candidate String by Edit Distance
This problem tests the implementation of the Levenshtein distance algorithm (Edit Distance) and the ability to manage tie-breaking logic when comparing multiple strings against a query.
Coding & AlgorithmsOnline AssessmentDynamic ProgrammingStringsOptimization - TeslaMediumBackend EngineerCompute time to burn tree
This question evaluates proficiency with tree algorithms, distance computation, and propagation modeling, testing the ability to reason about how a process spreads across parent-child relationships in a tree.
Coding & AlgorithmsOnsite - UberMediumBackend EngineerReplace Dashes With Nearest Letters
This problem tests your ability to perform a multi-source shortest path search on a grid to determine the influence of characters on empty spaces, using Manhattan distance and lexicographical tie-breaking.
Coding & AlgorithmsTechnical ScreenBFSGridGraph
Airwallex
Applied Intuition
Chime
Coinbase
Databricks
Harvey
Instacart
Meta
Nuro
OpenAI
Oracle
Robinhood
Spotify
Tesla
Uber