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Software 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.
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- 11
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Showing 691–720 of 2336 results
- 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 - DatabricksMediumSoftware EngineerReferral Credit Tracker with Indirect Referrals
Build a referral credit tracker with account creation, threshold queries, deterministic ordering, and correct credit propagation through indirect referrals.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerReport the Winner After Every Move on an n x n Tic-Tac-Toe Board
Process a sequence of alternating tic-tac-toe moves on an n x n board and report, after every move, whether player 1 or player 2 has just completed a full row, column, main diagonal or anti-diagonal. Tests efficient incremental win detection, diagonal indexing and correct handling of draws.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerSingle-Machine Cache with WAL Persistence, Sharded Locks and LRU
Design and write pseudocode for a single-machine in-memory cache behind a web service, then add write-ahead-log persistence, shard it to cut lock contention, shrink critical sections, find deadlocks by inspection, and explain LRU eviction built from a linked list and a hash map.
System DesignOnsite - DatabricksMediumSoftware EngineerThread-Safe Durable Event Writer Shared by Thousands of Threads
Design a thread-safe DataWriter whose push method durably appends opaque records of up to 1 KB to one local file while thousands of threads call it at once. Tests durability contracts, batching disk syncs across callers, crash-safe record framing and handling of failed writes.
System DesignOnsite - DatabricksMediumSoftware EngineerTic-Tac-Toe Against a Deterministic Automatic Opponent
Build an automated Tic-Tac-Toe opponent with perfect-play minimax, deterministic move ties, board events, invalid attempts, and terminal-state handling.
Coding & AlgorithmsOnsite - DatabricksMediumSoftware EngineerTic-Tac-Toe with Automatic Turns and Board Snapshots
Implement two-player Tic-Tac-Toe with automatic turn changes, board snapshots, rejected moves, winning lines, and full-board draws.
Coding & AlgorithmsOnsite - DatadogMediumSoftware EngineerCompute sliding window sums by tag
This question evaluates understanding of sequence processing, sliding-window aggregation, filtering by tag, and efficient state management in tagged time-series or event data, testing algorithmic efficiency and correctness.
Coding & AlgorithmsOnsite - DatadogEasySoftware EngineerEngineering Manager Interview: Your Technical Contribution and an Annoying Teammate
A hiring manager conversation for an engineering manager role: introduce yourself, explain your own technical contribution to a project you led, and describe a time a team member annoyed you. It tests whether a manager can separate personal technical judgment from team output and handle interpersonal friction with candor.
Behavioral & LeadershipOnsite - DatadogHardSoftware EngineerImplement Prefix Match Filter
This question evaluates understanding of prefix-based string matching, data structure design (hash-based sets and trie/prefix tree), and algorithmic competencies including efficient in-memory storage and deduplication of matches.
Coding & AlgorithmsOnsite - DatadogMediumSoftware EngineerImplement a Snowflake Query Client
This question evaluates API client design, asynchronous query lifecycle management, result retrieval, robust error handling, and secure credential handling for a cloud data warehouse.
Coding & AlgorithmsOnsite - DecagonMediumSoftware EngineerDesign a Single-Domain Chatbot
This question evaluates a candidate's ability to design production-grade conversational AI systems, testing competencies in retrieval-augmented generation, document ingestion and indexing, multi-turn session management, prompt construction, model serving, grounding and citation, safety, access control, monitoring, and operational trade-offs.
ML System DesignOnsite - DecagonMediumSoftware EngineerDesign the Security Architecture for an LLM Chatbot Product
A system design question on securing a chatbot built on a large language model that talks with people outside the company. It tests threat modeling for prompt injection and data leakage, user authentication and tool authorization outside the model, tenant isolation, sensitive-data handling, abuse controls, auditing and incident response.
System DesignOnsite - DecagonMediumSoftware EngineerEnumerate 4x4 Tic-Tac-Toe Games
This question evaluates understanding of recursion and backtracking, exhaustive game-tree enumeration, and state representation for combinatorial game analysis.
Coding & AlgorithmsOnsite - DecagonMediumSoftware EngineerImplement CSAT tracking and call timing
This problem tests your ability to manage stateful data during event processing and calculate exclusive execution times from a stream of nested function logs.
Coding & AlgorithmsOnsiteStackSimulationData Structures - DecagonMediumSoftware EngineerShopping Cart with Undo and Redo for Add and Remove Operations
A coding exercise to build a shopping cart class whose add and remove operations can be undone and redone. It tests how history entries are represented, how capped removals and deleted lines are reversed exactly, what a new change does to the redo history, and how empty-history cases are handled.
Software Engineering FundamentalsOnsite - DecagonMediumSoftware EngineerWalk Through a Project, a Project That Went Wrong, and How You Use AI
A culture-focused behavioral interview with three questions: describe a project you worked on, describe a project that went wrong, and explain how you use AI tools in your work. It tests clear ownership of decisions, honest reflection on failure, and practical judgment about verifying AI output and respecting its limits.
Behavioral & LeadershipOnsite - Deutsche BankHardSoftware EngineerAnswer mixed behavioral and technical deep-dive questions
This question evaluates a software engineer's combined behavioral and technical competencies, including communication, leadership, conflict resolution, system integration and API contracts, debugging, testing strategies, documentation practices, and use of AI tools.
Behavioral & LeadershipOnsite - Deutsche BankHardSoftware EngineerExplain Java follow-ups after solving coding problem
This question evaluates proficiency in Java programming and software engineering fundamentals, covering competencies such as refactoring for changing requirements, input validation, performance analysis for large datasets, selection of Java collections, generics, exception design, and unit testing.
Software Engineering FundamentalsOnsite
Databricks
Datadog
Decagon