Interview questions
Find a company or topic. Read the sources, then practice.
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Find a company or topic. Read the sources, then practice.
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Showing 1,376–1,400
A graph database with efficient adjacency access, bounded queries across machines, and correct edge updates during failures.
General practice
consistency · data-partitioning · distributed-queries · graph-storage
Entity identity, source conflicts, reversible merges, and fast graph reads as facts change.
General practice
data-consistency · data-provenance · entity-resolution · graph-traversal
Moving a changing dataset across a limited link: resumable bulk copy, change capture, independent integrity checks, and a fenced cutover.
Companies: Google, Oracle
bandwidth-management · change-data-capture · cutover · integrity-verification
Approximate live presence: define a viewer, expire abandoned sessions, deduplicate tabs, and serve counts for very hot pages.
Companies: Booking.com
deduplication · ephemeral-storage · hot-keys · polling
Applications that span days: external checks, valid approvals, recovery after failures, and one disbursement per loan.
General practice
audit-history · external-integrations · idempotency · reconciliation
High-volume logs with durable ingest, fast incident queries, tenant isolation, and different retention periods.
General practice
data-retention · ingest-overload-behavior · log-ingestion · search-indexing
Security-sensitive identity flows: password verification under attack, revocable sessions, and account recovery without takeover races.
Companies: Google, Gusto, Visa
account-recovery · authentication · consistency · password-security
Keep point balances correct across concurrent redemptions, repeated requests, purchase cancellations, and expiry.
General practice
auditability · balance-correctness · concurrent-redemptions · point-expiry
Map tiles across zoom levels: sparse demand, regional edits, cache deadlines, and render capacity.
General practice
backpressure · cache-invalidation · caching · geospatial-indexing
Playback licenses: subscription changes, device limits, country checks, and media key protection during failures.
General practice
authorization · availability · device-limits · drm
Text search across short metadata and long transcripts, with relevant results, timely catalog changes, and strict availability checks.
General practice
availability-rules · catalog-updates · search-maintenance · search-relevance
Daily merchant payouts with delayed financial events, fixed cutoffs, reserve rules, and uncertain transfer outcomes.
General practice
batch-processing · financial-ledger · idempotency · reconciliation
High-volume time-series ingestion: bounded cardinality, correct aggregation across retries and rollups, and alerts that distinguish unhealthy services from missing data.
Companies: Amazon, Atlassian, Datadog, eBay +5
aggregation · alerting · backpressure · high-cardinality
Regional recovery under time and data-loss objectives, with strict writer safety, shared dependencies, and uncertain cloud actions.
General practice
data-durability · dependency-management · disaster-recovery · recovery-objectives
Short-lived real-time races: authoritative progress and timing, bounded fanout, reconnects, and honest limits on cheat detection.
Companies: OpenAI
websockets · authoritative-state · matchmaking · backpressure
The service must find edited copies across billions of items without a full scan or long delays.
General practice
content-deletion · corpus-search-cost · ingestion-freshness · match-quality
Geographic search across uneven place density: correct boundaries, nearest results, and fresh data after place changes.
General practice
dense-area-load · distance-order · nearby-search · place-freshness
Fan-out on write vs read, celebrity hybrid, feed caches, outbox, ranking as an extension.
General practice
caching · denormalization · fan-out · hot-keys
Reserve one space for a complete time interval while keeping discovery results fresh and resolving payment failures.
General practice
cache-consistency · concurrency · geospatial-search · idempotency
Sparse, bidirectional compatibility lookups: product identity, conditional evidence, filtered discovery, and safe corrections.
General practice
cache-consistency · data-ingestion · data-modeling · entity-resolution
Private vaults across devices: key access, offline edits, shared access removal, and recovery with explicit security limits.
General practice
account-recovery · conflict-resolution · key-management · offline-sync
Companies: Netflix
Accurate spending totals across bank imports, repeated transactions, bank corrections, and user category changes.
General practice
bank-data-imports · budget-totals · category-precedence · concurrent-changes
Shared ordered playlists need clear conflict rules, stable entry identity, efficient page reads, and reliable change recovery.
General practice
access-control · concurrency-control · idempotency · ordered-data
Matching price streams against millions of thresholds: ordered evaluation, hot-instrument fanout, and reliable one-shot notifications.
Companies: Bloomberg, Coinbase, Meta, Swyftx +1
event-ordering · hot-keys · idempotency · notification-delivery