Side-by-side.
No hand-waving.
Head-to-head comparisons of the technologies you'll reference in every system design interview — databases, brokers, caching strategies, API protocols, and consistency models. Each includes a decision flowchart so you can justify your choice in 30 seconds.
Technology Comparisons
5 shippedMessage Brokers Compared
Every distributed system eventually needs asynchronous communication. The wrong broker choice leads to lost messages, impossible replay, or a $50k/month AWS bill. Kafka, RabbitMQ, SQS, and Redis pub/sub each solve a diff
Databases Compared
"Which database?" is the single most common design decision in every system design interview. Pick wrong and your design either can't scale, can't query, or can't stay consistent. PostgreSQL, MySQL, Cassandra, DynamoDB,
Caching Strategies Compared
Caching is the single biggest performance lever in any system. But "just add a cache" is a hand-wave — the strategy determines consistency, write amplification, and failure modes. Cache-aside, write-through, write-back,
API Protocols Compared
Every system design starts with "how do clients talk to your service?" REST, gRPC, GraphQL, WebSocket, and SSE are not interchangeable — each optimizes for a different communication pattern. Choosing the wrong protocol m
Consistency Models Compared
Every distributed system makes a consistency choice — explicitly or by accident. "Eventual consistency" gets thrown around in interviews like a magic wand, but there are at least five distinct models, each with different