System Design

Lessons

1. 1

   What System Design Is and Why It Matters

   Free

   Explain system design, the questions senior engineers ask, and the four building blocks of any system.

   Intermediate·30 min
2. 2

   Scalability Fundamentals and CAP Theorem

   Distinguish vertical vs horizontal scaling, stateless vs stateful, and reason about CAP and PACELC.

   Intermediate·45 min
3. 3

   Databases at Scale

   Apply read replicas, connection pooling, and sharding to scale a database past single-instance limits.

   Intermediate·50 min
4. 4

   Caching

   Apply cache-aside vs write-through patterns, design invalidation, and choose between Redis, CDN, and DB caches.

   Intermediate·40 min
5. 5

   Load Balancing

   Pick between round-robin and least-connections, design health checks, and implement graceful shutdown.

   Intermediate·35 min
6. 6

   Message Queues and Async Processing

   Decide when to introduce a queue and pick from Redis/RabbitMQ/SQS/Kafka for a specific workload.

   Intermediate·50 min
7. 7

   Designing a Real System (URL Shortener, Notifications, Twitter Feed)

   Walk through three canonical system-design problems end-to-end with the building blocks from earlier lessons.

   Advanced·90 min
8. 8

   Rate Limiting

   Apply token bucket and leaky bucket algorithms and decide where in the stack to enforce limits.

   Intermediate·35 min
9. 9

   Microservices vs Monolith

   Compare microservices vs monolith honestly, identify when each fits, and avoid the cargo-cult adoption pattern.

   Advanced·40 min
10. 10

    API Design: REST vs GraphQL vs gRPC

    Choose between REST, GraphQL, and gRPC, and design versioning, pagination, and idempotency correctly.

    Intermediate·45 min
11. 11

    Reliability and Fault Tolerance

    Reason about SLIs/SLOs/SLAs and design retries with backoff, circuit breakers, and graceful degradation.

    Intermediate·45 min
12. 12

    System Design Interview Job Readiness

    Structure a 45-minute system design interview and communicate tradeoffs to land mid-to-senior engineering offers.

    Intermediate·40 min