System design module

In progress. 13 of these 40 lessons are published; the other 27 are outlined and not yet written. All are listed so that pathways and the library can refer to them by their stable keys.

The mechanisms every design is built from, taught as trade-offs with numbers, plus classic and AI-era design exercises and the real-world practice of design docs, postmortems and migrations. Shared by every engineering pathway.

Part A. Foundations (17 lessons)

• Latency, throughput and back-of-envelope numberssd-numbers planned
• Networking for designerssd-networking planned
• Storage engines and indexessd-storage-engines planned
• Replication and partitioningsd-replication-partitioning planned
• Consistency models, transactions and consensus in plain wordssd-consistency-consensus planned
• Cachingsd-caching planned
• Queues, streams and delivery guaranteessd-queues-streams planned
• Load balancing and service discoverysd-load-balancing planned
• API designsd-api-design planned
• Data modelling across storessd-data-modelling planned
• Timeouts, retries and idempotencysd-idempotency-retries planned
• Rate limiting, overload and resilience patternssd-rate-limiting-overload planned
• Observability for designerssd-observability planned
• Capacity planning and performancesd-capacity planned
• Reliability, SLOs and failure modessd-reliability-slos planned
• Security basics in designssd-security-basics planned
• Cost as a design constraintsd-cost planned

Part B. Patterns (7 lessons)

• CQRS and event sourcingsd-cqrs-event-sourcing planned
• Sagas and distributed transactionssd-sagas planned
• Outbox and change data capturesd-outbox-cdc planned
• Fan-out, pub/sub and feedssd-fan-out planned
• Multi-tenancysd-multi-tenancy planned
• Cells, stamps and shuffle shardingsd-cells-shuffle-sharding planned
• Geo distribution and multi-regionsd-geo-distribution planned

Part C. Design exercises (13 lessons)

• URL shortener and key-value servicesd-ex-url-shortener published
• News feedsd-ex-news-feed published
• Chat and presencesd-ex-chat published
• Notificationssd-ex-notifications published
• API rate limitersd-ex-rate-limiter published
• Search autocompletesd-ex-autocomplete published
• File storage and syncsd-ex-file-storage published
• Payments ledgersd-ex-payments-ledger published
• Metrics and time series pipelinesd-ex-metrics-pipeline published
• Ride matching and locationsd-ex-ride-matching published
• RAG service (retrieval-augmented generation)sd-ex-rag-service published
• LLM gatewaysd-ex-llm-gateway published
• Vector search servicesd-ex-vector-search published

Part D. Real-world practice (3 lessons)

• Design docs, ADRs and trade-off reviewssd-design-docs-adrs planned
• Incident postmortemssd-ex-postmortems planned
• Migration planssd-ex-migrations planned