System Design Drill Day 1: Latency, Throughput and Availability
What latency, throughput and availability really mean, and how to build a health-check endpoint that reports them honestly.

Series
Daily system design drills.
What latency, throughput and availability really mean, and how to build a health-check endpoint that reports them honestly.

How cache-aside caching with Redis works, how to choose TTLs, and how to stop a cache stampede from taking down your database.

Why slow work belongs on a queue, what at-least-once delivery means, and how retries and idempotency keep background jobs safe.

How MySQL read replicas scale reads, why replication lag breaks read-your-writes, and how to handle it in Laravel.

How to go from one Laravel server to three behind a load balancer: algorithms, health checks, stateless servers and safe deploys.

How to split a MySQL orders table across shards: choosing a shard key, routing with logical shards, keeping reports off the shards and resharding.
