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Software Engineering Fundamentals 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
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- 546
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- 11
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- 8
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Showing 121–150 of 448 results
- CoupangMediumSoftware EngineerAnagram Group Tracker with Add, Remove, and Largest-Group Queries: Read vs Write Trade-offs
Design an in-memory data structure that supports adding words, removing words, and querying the largest anagram group. Tests canonical key generation, dynamic maximum maintenance, and read-versus-write algorithmic trade-offs.
Software Engineering FundamentalsOnsitehash-tabledesignstrings - CrestaMediumSoftware EngineerBuild a Tool-Calling Chat Agent That Searches and Books Flights via a REST API
An AI-assisted coding round: turn a Python starter script into a terminal chat agent that uses LLM tool calling to search flights, save passenger details and book a flight through a three-endpoint REST API. It tests tool schemas, a multi-step tool loop, ID handling, booking safeguards and error handling.
Software Engineering FundamentalsOnsite - CrestaMediumSoftware EngineerDesign a Robust Feature Flag Evaluation Engine
Implement an in-memory feature flag evaluation engine that evaluates flags against user attributes using rule predicates, deterministic percentage rollouts, and a true-wins resolution policy.
Software Engineering FundamentalsOnsiteSoftware ArchitectureData StructuresHashing - CrowdstrikeMediumSoftware EngineerImplement an In-Memory Key-Value Cache with Expiry, Then Sketch a Redis-Like Server
Implement an in-memory key-value cache in the spirit of Redis, with get, set, delete and per-key expiry, then briefly discuss how a Redis-like server is built and where caches fit in a system. It tests data structure choices, expiry and eviction logic, thread safety, and practical knowledge of caching patterns.
Software Engineering FundamentalsOnsite - CrowdstrikeMediumSoftware EngineerReview a Sample Python Function Aloud and Label Every Finding by Severity
Review a short hypothetical Python function that builds a user profile from a database query and a billing-service call, narrating your reasoning aloud. The exercise tests how you read unfamiliar code and whether every comment is clearly labeled as must-fix, could-improve or a personal preference.
Software Engineering FundamentalsOnsite - DatabricksMediumSoftware EngineerAdd Sliding-Window Get and Put Activity Metrics to a Key-Value Store
Design and implement an in-memory key-value store that tracks read and write throughput (operations per second) over configurable sliding windows.
Software Engineering FundamentalsOnsitedata-structuressliding-windowsystem-design - DatabricksMediumSoftware EngineerBuild a Durable Key-Value Cache
This question tests the ability to design a crash-recoverable key-value store by implementing a write-ahead log (WAL) to ensure data durability and system integrity after an unexpected failure.
Software Engineering FundamentalsOnsiteSystems DesignDurabilityLogging - DatabricksHardSoftware EngineerDesign Snapshot Set Iteration and Clarify Durable Writes
Design a memory-efficient snapshotting set supporting concurrent mutations and isolated iteration, and define the reliability and persistence contracts required for durable writes.
Software Engineering FundamentalsOnsitemvccconcurrencystorage-engines - DatabricksHardSoftware EngineerDesign a Cache with Hit Counts
This question tests the ability to design a thread-safe, high-performance cache that maintains frequency metadata alongside data, requiring an understanding of efficient data structures and concurrency control.
Software Engineering FundamentalsOnsiteConcurrencyData StructuresHash Maps - DatabricksHardSoftware EngineerDesign a Key-Value Store with Hit Counting
Design a concurrent, in-memory key-value store that tracks read-access frequency using a sliding-window hit counter per key while keeping memory footprint bounded.
Software Engineering FundamentalsOnsiteconcurrencysliding-windowsystem-design - DatabricksHardSoftware EngineerDesign a Write-Ahead Log Writer with Batch Writes
Design and implement a concurrent write-ahead log (WAL) engine featuring group commit, monotonic sequence assignment, torn-tail crash recovery, and explicit durability promises.
Software Engineering FundamentalsOnsitestorage-enginesconcurrencysystems-programming - DatabricksMediumSoftware EngineerDesign a multithreaded event logger
This problem tests your ability to design a thread-safe, high-throughput logging system that balances memory efficiency with I/O performance under concurrent load.
Software Engineering FundamentalsOnsiteConcurrencyMultithreadingDesign Patterns - 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 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 - 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 - 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 - 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 - 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 - 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 - DigitaloceanMediumSoftware EngineerClarify a Longest-Repeating-Character Replacement Problem
Clarify replacement and substring semantics, then analyze the conditional sliding-window criterion based on window size and maximum character frequency.
Software Engineering FundamentalsOnsite - DigitaloceanMediumSoftware EngineerSpecify House-Selection Constraints Before Choosing a Robbery Dynamic Program
Clarify house layout and selection conflicts, derive a conditional linear dynamic program, and explain how circular or graph constraints change it.
Software Engineering FundamentalsOnsite - DiscordMediumSoftware EngineerDemonstrate effective AI-assisted coding workflow
This question evaluates a candidate's proficiency with AI-assisted coding workflows, including prompt formulation, tool and library selection, design critique, testing approaches, and iterative feature development to demonstrate engineering judgment and ownership.
Software Engineering FundamentalsOnsite - DisneyMediumSoftware EngineerBuild a sortable, searchable movie list UI
This question tests the ability to design a performant, reactive frontend component that handles data manipulation, asynchronous API integration, and efficient DOM rendering.
Software Engineering FundamentalsOnsiteFrontendReactPerformance - DisneyEasySoftware EngineerHow would you run a mentoring-focused code review?
This question evaluates mentoring-focused code review competencies, including code quality and maintainability analysis, frontend architecture (React/TypeScript), testing strategy, accessibility and security awareness, plus written and interpersonal feedback skills.
Software Engineering FundamentalsOnsite - DisneyEasyData EngineerPrompting an LLM to Migrate a Java Codebase to Python and Clean a Large Database
Explain how you would prompt a large language model to migrate a Java codebase to Python and to help clean a database with tens of thousands of rows. It tests prompt design, verification of generated code and data fixes, data quality measurement, security of AI-assisted work and the handling of sensitive data.
Software Engineering FundamentalsOnsite - DocuSignEasySoftware EngineerDesign a JSON Schema Validator
Design and implement a modular JSON schema validator that verifies data against structural schemas, supporting primitive types, nested objects, arrays, regex patterns, numeric ranges, and strict field controls.
Software Engineering FundamentalsOnsiterecursionoopdesign - DoorDashMediumSoftware EngineerBootstrap Service: Aggregate Downstream Services and Return the Right HTTP Status
Implement a bootstrap service that calls several independent downstream services concurrently, aggregates their data into one response for a client app, and returns an HTTP status code that reflects partial or total failure. It tests concurrent calls, timeouts, per-section error reporting, and mapping downstream failures to client-facing status codes.
Software Engineering FundamentalsOnsite - DoorDashMediumSoftware EngineerBuild Resilient Aggregation and Debug Routing
This question evaluates skills in building resilient API aggregation, fault-tolerant retry handling and test coverage for transient failures, as well as debugging and improving load-balancer routing policies including adding round-robin distribution and reasoning about consistent hashing.
Software Engineering FundamentalsOnsite - DoorDashMediumSoftware EngineerBuild Two Interacting Services That Carry Out a Realistic Refund Flow
A senior coding exercise, with an AI assistant allowed, to build two cooperating services that carry out a refund end to end. It tests service boundaries, a refund state machine, idempotent retries, handling of declines and timeouts, and a runnable simulation of realistic refund scenarios.
Software Engineering FundamentalsOnsite - DoorDashMediumSoftware EngineerBuild a Resilient Bootstrap API with Partial Upstream Results
Combine Consumer, Payment, and Address APIs with correct identifier dependencies, partial success, bounded timeouts, and complete response fields.
Software Engineering FundamentalsOnsite
Coupang
Cresta
Crowdstrike
Databricks
Decagon
Discord
Disney
DocuSign
DoorDash