Topic
Software Engineering Fundamentals interview questions
1208 Software Engineering Fundamentals questions from 253 companies, with hints, runnable code and solution walkthroughs.
123 easy887 medium198 hard
Software Engineering Fundamentals interview questions by the numbers
Last updated
Katkat has 1,208 Software Engineering Fundamentals interview questions from 253 companies; the most come from OpenAI (5%), Stripe (4%) and Amazon (3%). By difficulty: 10% easy, 73% medium and 16% hard. The most common round is Technical Screen (52%). Frequent concepts include Data Structures, Concurrency, System Design and Algorithms.
Companies (253)
Difficulty
- Easy10% · 123
- Medium73% · 887
- Hard16% · 198
Interview rounds
- Technical Screen52% · 625
- Onsite37% · 448
- Online Assessment8% · 96
- HR Screen2% · 28
- Other1% · 11
Roles
- Software Engineer85% · 1026
- Frontend Engineer4% · 51
- Machine Learning Engineer2% · 30
- Backend Engineer2% · 25
- Data Scientist1% · 17
Frequent concepts
- Data Structures8% · 97
- Concurrency8% · 96
- System Design8% · 93
- Algorithms3% · 42
- API Design3% · 42
- Object-Oriented Design3% · 35
Most mentioned in interview experiences
- 1.Plant Infection Grid Simulation: Days to Stabilize, Immune Plants, Expiring Immunity5 reports
- 2.Bootstrap Service: Aggregate Downstream Services and Return the Right HTTP Status4 reports
- 3.Crawl an HTTP-served maze to its exit with 503 retries, dead ends and cycles4 reports
- 4.Find the Exit of an HTTP URL Maze Despite Flaky 503s and Bad JSON4 reports
- 5.In-Memory Workspace Credit System With Transfers, Top-K and Scheduled Transfers4 reports
- 6.Virtual Card Case Study: Trade-offs, Card Number Rule Checks, and Debugging a Filter4 reports
- 7.Virtual Card Numbers Case: Trade-offs, Payment Validation Rules, Debugging4 reports
- 8.Workspace Credit Ledger: Transfers, Top-K, Scheduled Transfers, Merges, Balance History4 reports
- 9.Build a UVM testbench: driver, monitor, scoreboard and coverage-driven closure3 reports
- 10.Debug a Layered Book Search Service Against Five Search Rules3 reports
Counted from 425 candidate interview experiences on Katkat. How we collect and count
Showing 391–420 of 1208 results
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.
DisneySoftware EngineerSoftware Engineering FundamentalsOnsiteTests low-level data structure design by implementing a set from scratch using an array-backed hash table, focusing on collision resolution, dynamic resizing, load factor management, and amortized complexity.
DisneySoftware EngineerSoftware Engineering FundamentalsTechnical ScreenExplain 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.
DisneyData EngineerSoftware Engineering FundamentalsOnsiteDesign and implement a thread-safe batch buffer that collects streaming records from multiple producer threads and flushes them to a database using batch inserts based on size, timeout, or shutdown triggers.
DisneySoftware EngineerSoftware Engineering FundamentalsTechnical ScreenDesign 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.
DocuSignSoftware EngineerSoftware Engineering FundamentalsOnsiteImplement 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.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis 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.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteA 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.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteBuild a payout endpoint that retrieves delivery activity and accrues 30 cents per minute for each concurrent order. The solution covers interval sweeps, malformed events, exact money, day boundaries, final rounding, upstream timeouts, retry limits, caching, and layered tests.
DoorDashSoftware EngineerSoftware Engineering FundamentalsTechnical ScreenCombine Consumer, Payment, and Address APIs with correct identifier dependencies, partial success, bounded timeouts, and complete response fields.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteBuild a continuously running Python system of separate services that executes a small workflow graph in which late orders trigger refunds, then discuss new features, API evolution, adding payments, and testing. It tests scoping under time pressure, service boundaries, idempotent refunds, and effective AI-assisted development.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteImplement and orchestrate a multi-service refund pipeline over HTTP, ensuring idempotent execution, safe concurrency limits, and crash recovery across separate process boundaries.
DoorDashSoftware EngineerSoftware Engineering FundamentalsTechnical ScreenDesign and demonstrate a local service for missing or delayed orders, with explicit refund rules, duplicate handling, and auditable decisions.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteA DoorDash onsite exercise to finish and debug starter code for a service that assigns delivery drivers to orders. It tests constant-time bookkeeping, defending a list versus hash map storage choice, invariant-based testing, and how to make the service safe and scalable in production.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteDoorDash software-engineer onsite front-end question: compare Redux with modern state and data management approaches (Redux Toolkit/RTK Query, React Query, SWR, Zustand, Recoil, MobX, Context) and design an end-to-end strategy for a React SPA that needs offline viewing, pagination, optimistic updates, and error retries. It tests separating client UI state from server cache, caching/invalidation, performance, type safety, testing, and an incremental migration plan off Redux.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis problem tests the ability to identify flaws in load balancing implementations by evaluating consistency, distribution, and edge-case handling in Round-Robin and Consistent Hashing logic.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteDebug a random dasher registry backed by a dense array and an ID-to-index map. Repair empty and swap-delete edge cases, preserve representation invariants, narrow error handling, and extend the design for concurrency and slow dependencies.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteDebug a round-robin load balancer that must keep strict rotation while servers are added and removed, then implement a consistent-hash ring that gives each key a stable server. It tests off-by-one and index-mutation bugs, thread safety, stable hashing, virtual nodes, lookup cost, and how many keys move on membership changes.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis question evaluates a candidate's ability to diagnose and debug production cache incidents, testing competencies in distributed caching, observability, incident response, root-cause analysis, and the operational impact on microservice latency.
DoorDashSoftware EngineerSoftware Engineering FundamentalsTechnical ScreenImplement and test an O(1) randomized pool that avoids and deterministically tests against the classic self-swap regression when removing the tail element.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis problem tests the ability to architect a robust, fault-tolerant workflow engine capable of managing complex state transitions and ensuring transactional integrity in distributed systems.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteDesign a resilient bootstrap aggregation service that fetches critical initial state for a mobile app on launch. Tests interface design, concurrent I/O, partial failure handling, and operational trade-offs.
DoorDashSoftware EngineerSoftware Engineering FundamentalsTechnical ScreenAssesses the candidate's ability to design robust HTTP APIs covering endpoint modeling, request/response schemas, datetime formats, idempotency strategies, retry semantics, validation/error codes, and observability for pay-computation services.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnline AssessmentExplain a project's most complex technical component through its invariants, design alternatives, implementation details, and failure-case validation.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteImplement an orchestrator service that coordinates calls to a directory API and an operating-hours API with bounded concurrency, short-circuit filtering, resilient error handling, and in-memory caching.
DoorDashSoftware EngineerSoftware Engineering FundamentalsTechnical ScreenA debugging-style coding round on request routing: make a round-robin load balancer behave correctly as servers join and leave, then implement consistent hashing so requests with the same key stay on the same server. It tests careful state handling, concurrency, edge cases such as an empty pool, and reasoning about how many keys move when membership changes.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis question evaluates a candidate's competence in designing fault-tolerant payment workflows and operational resilience, covering concepts such as idempotency, retry strategies, queuing and dead-letter handling, circuit breaking, reconciliation, and monitoring.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteTests your ability to critically evaluate, debug, and refactor AI-generated code for a real-time order batching service under concurrent access, edge-case constraints, and strict correctness requirements.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis question evaluates proficiency in front-end engineering, including CSS utility system design, responsive grid layout, semantic HTML, accessibility (ARIA and focus management), form validation, asynchronous submission patterns, and lightweight JavaScript for interactivity and telemetry.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsiteThis problem tests your ability to implement a distributed hashing mechanism that minimizes data movement when adding or removing nodes.
DoorDashSoftware EngineerSoftware Engineering FundamentalsOnsite