← Back to System Design overview

Hand-written tutorials, ordered as a recommended learning path.

1. 41 CQRS Learn how CQRS separates read and write models for better scalability. Covers architecture, implementation patterns, and when CQRS is worth the complexity. 7 min read →
2. 42 Event Sourcing Understand event sourcing fundamentals, how it differs from CRUD, when to use it, and the real-world trade-offs you need to consider before adopting it. 7 min read →
3. 43 Idempotency Patterns Learn how to design idempotent APIs and achieve exactly-once semantics using idempotency keys, deduplication stores, and transactional outbox patterns. 7 min read →
4. 44 Saga Pattern Learn how the saga pattern coordinates transactions across microservices using choreography and orchestration, with compensation logic for rollbacks. 7 min read →
5. 45 Service Mesh Understand how service meshes handle traffic management, observability, and security in microservices using sidecar proxies like Envoy and platforms like Istio. 8 min read →
6. 46 Search Autocomplete A system design deep dive into building search autocomplete: trie data structures, ranking algorithms, caching strategies, data collection pipelines, and real-time update mechanisms. 8 min read →
7. 47 CAP Theorem A pragmatic look at the CAP theorem: what consistency and availability mean for real workloads, and how PACELC describes the trade-offs better. 5 min read →
8. 48 Consistent Hashing How consistent hashing actually works in production: virtual nodes, rebalancing, hot keys, and why naive modulo hashing fails at scale. 5 min read →
9. 49 Rate Limiters A senior-engineer guide to designing rate limiters: algorithms, distributed coordination, trade-offs, and production patterns that actually scale. 5 min read →
10. 50 Redis Locks A practical look at distributed locking with Redis: SET NX EX, Redlock, fencing tokens, and the failure modes that cause data corruption. 5 min read →
11. 51 Event-Driven What event-driven architecture really gives you, when to choose it, and the operational realities of running asynchronous systems at scale. 5 min read →
12. 52 Kafka vs Rabbit A senior-engineer comparison of Kafka and RabbitMQ: log vs queue semantics, throughput, ordering, retention, and the real selection criteria. 5 min read →
13. 53 Chat App Design a real-time chat system that supports millions of users with low latency messaging, presence, and message persistence at scale. 3 min read →
14. 54 Dist. Cache Design a distributed cache using consistent hashing, replication, and eviction policies to speed up reads at internet scale. 3 min read →
15. 55 File Storage Design a file storage service with uploads, sync, deduplication, and sharing, scaling to petabytes while keeping reads fast and cheap. 3 min read →
16. 56 Leaderboard Design a real-time leaderboard using Redis sorted sets, handling millions of score updates per second with low latency rankings. 3 min read →
17. 57 Notifications Design a notification service that delivers email, SMS, and push reliably with templating, rate limits, retries, and user preferences. 3 min read →
18. 58 Payments Design a payment gateway with idempotency, double-entry ledgers, retries, and PCI considerations, balancing safety and throughput. 3 min read →
19. 59 7-Step SD Framework A repeatable 7-step framework for system design interviews. Clarify, estimate, API, data model, high-level, deep dive, bottlenecks — with concrete examples for each step. 5 min read →
20. 60 Distributed Cache Design a distributed in-memory cache like Redis or Memcached. Covers consistent hashing, replication, eviction, persistence, and surviving node failures cleanly. 6 min read →