System DesignPractice 75

Complete course · self-paced

System Design

Turn ambiguous prompts into clear, defensible architectures—then practice explaining every trade-off.

Modules
5
Lessons
68
Access
Open
Start here01
Overview · 4 min

Introduction

Learn the highest-leverage system design interview loop: scope, model, architecture, deep dive, and close.

Begin lesson
Curriculum

Learn in sequence

Each module moves from mental model to worked application.

01

Module 01

Overview

Understand the interview formats, the evaluation signals, and the fastest useful path through the course.
3 lessons
  1. 01IntroductionLearn the highest-leverage system design interview loop: scope, model, architecture, deep dive, and close.4 min
  2. 02Types of system design interviewsDistinguish product, infrastructure, object-oriented, and ML system design prompts.7 min
  3. 03What to expect from coachingRecognize the red flags interviewers see, understand the scoring rubric, and rehearse a realistic mock loop.8 min
02

Module 02

Key concepts

A compact sequence for turning an ambiguous prompt into a legible, defensible architecture.
4 lessons
  1. 01RequirementsClarify users, critical flows, constraints, traffic, storage, latency, and availability before drawing boxes.8 min
  2. 02Entities and APIsDerive durable nouns and high-value operations directly from the agreed functional requirements.8 min
  3. 03High Level DesignTrace read and write paths through the smallest architecture that can satisfy the target scale.10 min
  4. 04Deep DivesIdentify the riskiest decision, invite a probe, and reason through trade-offs without losing the system narrative.10 min
03

Module 03

Building blocks

Know the job, trade-offs, bottlenecks, and failure behavior of the components that recur across designs.
11 lessons
  1. 01DatabasesChoose relational, key-value, document, wide-column, graph, or time-series storage from access patterns and guarantees.8 min
  2. 02CachingUse cache-aside, write-through, and write-behind strategies while making invalidation and hot keys explicit.8 min
  3. 03Load balancersDistribute traffic, detect unhealthy instances, preserve affinity only when necessary, and remove single points of failure.8 min
  4. 04Message queuesDecouple work with durable delivery, consumer groups, retries, dead letters, ordering, and backpressure.8 min
  5. 05Blob storageSeparate immutable large objects from metadata and design multipart upload, durability, and lifecycle policies.8 min
  6. 06Content Delivery Networks (CDN)Move cacheable content to the edge and reason about origins, invalidation, regional latency, and signed access.8 min
  7. 07Rate limitersCompare token bucket, leaky bucket, fixed window, and sliding window strategies for distributed enforcement.8 min
  8. 08API gatewaysCentralize routing, authentication, quotas, and request shaping without turning the edge into an opaque bottleneck.8 min
  9. 09Search systemsDesign ingestion, inverted indexes, ranking, sharding, and freshness for high-volume full-text retrieval.8 min
  10. 10Write-ahead loggingUse append-first durability for recovery, replication, and change streams while managing compaction.8 min
  11. 11How LLM Inference Actually WorksFollow tokens through batching, prefill, KV cache, decoding, scheduling, and GPU memory constraints.11 min
04

Module 04

Questions

Apply the method to product, infrastructure, developer-tool, financial, and AI systems.
26 lessons
  1. 01Ad click aggregatorDesign high-volume event ingestion with deduplication, streaming aggregation, late data, and auditable totals.35 min
  2. 02ChatGPT PlaygroundDesign low-latency token streaming, conversation state, model routing, safety checks, and usage metering.35 min
  3. 03CI/CD systemDesign workflow DAGs, isolated runners, artifacts, logs, retries, and fair scheduling for bursty builds.40 min
  4. 04Crossword puzzle solverDesign a distributed constraint solver with bounded search, indexed candidates, parallel tasks, checkpoint recovery, and exactly one terminal result.45 min
  5. 05Distributed cacheDesign partitioning, replication, eviction, consistency, hot-key protection, and node rebalancing.35 min
  6. 06Online chessDesign authoritative game state, matchmaking, move validation, clocks, reconnection, and spectator fan-out.30 min
  7. 07Distributed file systemDesign metadata, chunk placement, replication, checksums, repair, and namespace consistency.40 min
  8. 08Meta Post PrivacyDesign audience policy evaluation, graph-aware authorization, caching, and privacy-safe fan-out.30 min
  9. 09Google CalendarDesign recurring events, invitations, time zones, conflict handling, reminders, and concurrent updates.35 min
  10. 10Google MapsDesign geospatial indexing, tile delivery, live traffic ingestion, and route computation.40 min
  11. 11Job schedulerDesign durable schedules, leases, worker heartbeats, retries, priorities, and exactly-once effects.35 min
  12. 12LeaderboardDesign rank updates, top-K queries, tie handling, seasons, and hot-partition control.30 min
  13. 13LeetCodeDesign secure code execution, sandbox pools, test orchestration, result streaming, and contest bursts.40 min
  14. 14Online bookstoreDesign catalog search, inventory, carts, orders, reservations, and payment-safe checkout.30 min
  15. 15Distributed countersDesign high-write counters with sharding, approximation, aggregation, and monotonic reads.30 min
  16. 16Payment systemDesign payment intents, idempotency, ledgers, authorization, settlement, reconciliation, and webhooks.45 min
  17. 17Remote DevboxDesign secure workspace provisioning, lifecycle control, persistent volumes, terminals, and low-latency streaming.40 min
  18. 18SlackDesign conversations, ordered delivery, offline sync, presence, search, and attachment storage.35 min
  19. 19Top-K videosDesign streaming popularity scores across windows while controlling skew, freshness, and ranking cost.30 min
  20. 20UberDesign nearby-driver discovery, matching, live locations, trip state, pricing, and regional failover.40 min
  21. 21Webhook delivery systemDesign subscriptions, signing, durable delivery, exponential retry, idempotency, and tenant isolation.35 min
  22. 22YelpDesign proximity search, geospatial indexing, ranking, reviews, and read-heavy caching.30 min
  23. 23Batch inference systemDesign large job admission, GPU-aware scheduling, checkpointing, artifacts, and cost-aware throughput.40 min
  24. 24ML model distributionDesign versioned artifacts, regional rollout, integrity checks, caching, rollback, and fleet convergence.35 min
  25. 25URL shortenerDesign unique keys, redirects, abuse controls, analytics, cache strategy, and expiration.25 min
  26. 26Design SoraDesign asynchronous GPU workflows, prompt moderation, progress updates, durable media, and capacity controls.40 min
05

Module 05

Design patterns

Recognize the recurring shape of hard problems so your solution starts from an invariant, not a memorized product diagram.
24 lessons
  1. 01IntroductionMap requirements to reusable data, coordination, delivery, and scaling patterns.8 min
  2. 02Scaling readsLayer replicas, caches, denormalized views, and CDNs while controlling staleness.8 min
  3. 03Scaling writesPartition ingestion, batch work, serialize conflicts, and absorb bursts without losing durability.8 min
  4. 04Distributed cachingCombine placement, replication, invalidation, eviction, and stampede protection.8 min
  5. 05Rate limitingTranslate product quotas and protection goals into enforceable distributed budgets.8 min
  6. 06Handling large blobsUse direct transfer, chunking, checksums, metadata indirection, and background processing.8 min
  7. 07Unique ID generationCompare UUIDs, database sequences, range allocation, and Snowflake-style sortable IDs.8 min
  8. 08Time-series metrics ingestionDesign append-heavy collection, aggregation windows, retention, downsampling, and cardinality controls.8 min
  9. 09Search and full-text indexingSeparate source-of-truth writes from asynchronous indexing, ranking, and retrieval.8 min
  10. 10Idempotency and Exactly-Once SemanticsMake retries safe with stable operation keys, atomic state transitions, and deduplicated side effects.8 min
  11. 11Event sourcing and CQRSSeparate commands from query projections and understand replay, evolution, and consistency costs.8 min
  12. 12Dealing with ContentionChoose optimistic control, locks, queues, reservations, or single-writer ownership for shared state.8 min
  13. 13Multi-step processes and sagasCoordinate long business workflows with persisted state, compensations, and visible partial failure.8 min
  14. 14Job schedulingTurn future work into durable, claimable tasks with clocks, leases, fairness, and retries.8 min
  15. 15Pushing real-time updatesChoose WebSockets, server-sent events, long polling, or push notifications by delivery need.8 min
  16. 16Reservation Availability CheckingPrevent overselling with holds, expirations, atomic inventory updates, and reconciliation.8 min
  17. 17Fan-out and feed generationBalance write-time and read-time fan-out with celebrity handling and ranked retrieval.8 min
  18. 18Publish/subscribe messagingDesign topic ownership, durable offsets, consumer groups, ordering, and replay.8 min
  19. 19Proximity-based servicesUse spatial indexes, cell systems, moving-object updates, and distance-aware ranking.8 min
  20. 20Collaborative editingReason about operations, ordering, convergence, presence, snapshots, and offline edits.8 min
  21. 21Stream processing and real-time aggregationDesign windows, watermarks, state, checkpoints, reprocessing, and late-event policy.8 min
  22. 22Web crawling and data pipelinesDesign frontier queues, politeness, deduplication, parsing, lineage, and incremental refresh.8 min
  23. 23Managing long-running tasksExpose progress, cancellation, checkpointing, leases, retries, and result retention.8 min
  24. 24Payment Systems & Financial ConsistencyUse ledgers, idempotent commands, reconciliation, audit trails, and explicit settlement states.11 min