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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 901–930 of 2810 results
- DoorDashMediumSoftware EngineerDesign a Customer Review Page
This question tests the ability to design a scalable review system capable of handling high-write volume, media storage, and efficient retrieval with pagination.
System DesignTechnical ScreenAPIDatabaseScalability - DoorDashMediumSoftware EngineerDesign a Resilient Bootstrap API Aggregator
Design 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.
Software Engineering FundamentalsTechnical ScreenAPI DesignConcurrencyResilience - DoorDashHardSoftware EngineerDesign a notification system
This question evaluates a candidate's competency in designing scalable, reliable multi-channel notification platforms, covering distributed systems, multitenancy, API and storage schema design, queuing and retry strategies, rate limiting, observability, localization, A/B testing, and compliance considerations like GDPR.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerDesign a resilient bootstrap API
This question evaluates skills in resilient API aggregation, fault-tolerant microservice orchestration, and reliability engineering, focusing on defining API contract semantics and handling partial failures at the architectural/system-design level (service-to-service abstraction); category/domain: System Design.
System DesignTechnical Screen - DoorDashHardSoftware EngineerDesign a resilient dasher payment system
A DoorDash software-engineer system-design interview question: design a resilient Dasher payment system that computes payouts from order lifecycle events (accept/fulfill/cancel). It spans event-driven ingestion, idempotency and exactly-once-vs-at-least-once semantics, data modeling for high write throughput and per-dasher pay-period queries, timezone/DST handling, detection and remediation of missing or out-of-order data, batch-vs-streaming reconciliation, reliability, and consistency trade-offs.
System DesignTechnical Screen - DoorDashHardSoftware EngineerDesign a scalable Instagram-like platform
Design a scalable Instagram-like platform evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - DoorDashHardSoftware EngineerDesign a service aggregator with robust error handling
Design a service aggregator with robust error handling evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerDesign a single-machine LRU cache
This question evaluates a candidate's ability to design an efficient in-memory LRU cache and apply concurrency control, covering eviction semantics, capacity management, key updates, and synchronization for thread safety.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerDesign an Alert Notification Service for Downstream Consumers
Design a reliable, scalable alert and event notification delivery platform that decouples upstream producers from heterogeneous downstream consumers with independent fan-out, isolation, retries, and dead-letter handling.
System DesignTechnical ScreenDistributed SystemsMessage QueuesEvent-Driven - DoorDashMediumSoftware EngineerDesign consistent hashing with a sorted map
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 Design consistent hashing with a sorted map states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerDesign hierarchical path store with create/set/get/remove
This question evaluates a candidate's competency in hierarchical data structures, path parsing, API semantics, error signaling, complexity analysis, and unit testing for implementing a UNIX-style key-value path store.
Coding & AlgorithmsTechnical Screen - DoorDashHardSoftware EngineerDesign limited-time donation platform
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 Design limited-time donation platform states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - DoorDashHardSoftware EngineerDesign notification and project architecture
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 Design notification and project architecture states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerDetermine equality after limited swaps
This question evaluates string manipulation and combinatorial reasoning about character swaps and anagram formation, focusing on competencies such as frequency analysis and reasoning about minimal edit operations.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerDiscuss Projects and Planning Improvements
This question evaluates ownership, product understanding, end-to-end project leadership, cross-functional collaboration, and the ability to quantify impact within behavioral and leadership competencies for software engineers.
Behavioral & LeadershipTechnical Screen - DoorDashMediumSoftware EngineerDiscuss feedback, help, and conflict
This question evaluates interpersonal and leadership competencies such as receiving and acting on constructive feedback, mentoring or helping colleagues, and managing conflict within engineering teams (Behavioral & Leadership).
Behavioral & LeadershipTechnical Screen - DoorDashMediumSoftware EngineerFilter Open Restaurants Through Existing Domain APIs
Implement 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.
Software Engineering FundamentalsTechnical Screenconcurrencycachingsystem-integration - DoorDashMediumSoftware EngineerFind names similar by one swap
This question evaluates string manipulation, character-frequency analysis, and algorithmic reasoning to determine near-matches under a single-character-swap constraint.
Coding & AlgorithmsTechnical Screen - DoorDashHardSoftware EngineerHandle a payment-service incident with resource spikes
Handle a payment-service incident with resource spikes evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - DoorDashMediumSoftware EngineerHandling Duplicate Upstream Order Records in Dasher Pay Calculation
Explain how a Dasher pay calculation driven by upstream order records stays correct when those records contain duplicates. Tests deciding when two records describe the same fact, making processing safe against replayed records, handling conflicting and late data or corrections after payout, and preventing double payouts.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerImplement a hierarchical key-value store
Implement a hierarchical key-value store evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerImplement consistent hashing ring
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Implement consistent hashing ring states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerImplement dasher active-time calculator
This question evaluates competency in time-based event processing, pairing related events, computing durations using LocalDateTime and Duration APIs, and analyzing algorithmic time and space complexity.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerImplement string matching with follow-up
A DoorDash software-engineer coding screen on string matching: implement firstIndex(T, P) in O(|T| + |P|) time and O(|P|) space using KMP, then handle follow-ups on naive vs KMP vs Rabin–Karp, Unicode and very long inputs, edge cases, wildcard ('?'/'*') matching, and simultaneous multi-pattern search via Aho–Corasick. Includes corrected, complete solutions and complexity trade-offs.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerImplement string-path file system operations
This question evaluates competency in designing data structures for hierarchical string-path file systems, including string parsing, stateful API semantics, validation logic, and efficient lookup/update operations.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerMake a Courier Pay Workflow Resilient to Downstream Failures
Tests your ability to implement an idempotent, fault-tolerant workflow engine that safely executes financial transactions against an unreliable downstream ledger.
Software Engineering FundamentalsTechnical ScreenDistributed SystemsIdempotencyAPI Design - DoorDashMediumSoftware EngineerPaying Dashers Reliably When the Payment Service Is Unavailable
A system design follow-up about paying delivery drivers when the downstream payment service is unavailable. It tests reasoning about timeouts with unknown outcomes, durable records of amounts owed, retries that must never double-pay, recovery after long outages, reconciliation, and what drivers and operators see while payouts are delayed.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerPooled Rideshare Earnings With Concurrent Rides and Surge
Compute a pooled-ride driver's total earnings where each minute's pay scales with how many riders are currently in the car, and minutes inside non-overlapping surge windows pay double, testing sweep-line interval counting with exact half-open boundaries and 64-bit totals.
Coding & AlgorithmsTechnical Screensweep-lineintervalsarrays - DoorDashMediumSoftware EngineerProtect SLA and Choose Storage
This question evaluates system design competencies in service reliability and storage architecture, focusing on SLA protection during upstream latency spikes and trade-offs in choosing in-memory caches (e.g., Redis), relational databases, or alternative storage for order and payment state.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerRecover a Project That Has Gone Off Track
This question assesses a candidate's ability to demonstrate leadership, analytical rigor, and project management skills when facing technical or execution failures.
Behavioral & LeadershipTechnical ScreenLeadershipProject ManagementCommunication
DoorDash