System Design
One transposed letter in my.cnf and a healthy database refuses to start. innodb_buffer_pool_size becomes innodb_buffer_pool_sze, you restart, and the service is down, always during an automated deploy or an upgrade or right as you were leaving, never during a calm maintenance window. MariaDB
System Design
KVM is the virtualization layer underneath most of the Linux world you already touch — Proxmox, oVirt, OpenStack, and every "KVM VPS" you've ever rented all sit on it. It's built into the kernel, it's been production-grade for well over a decade,
System Design
A benchmark number drops, and within a day half your feed is repeating it: engine X demolished engine Y, here's the chart, end of discussion. The number feels objective. It's a measurement, after all. The trouble is that a database benchmark almost never measures the one
System Design
The Few Seconds the User Sees, the Millions of Transactions They Don't Every day, millions of people order food, stream videos, send messages, book rides, make payments, and shop online. From the user's perspective, each action takes a few seconds. Click a button, get a response,
System Design
The Scaling Problem Nobody Sees Coming Your first scaling problem rarely arrives with a bang. For a while, everything works: pages load fast, the database barely breaks a sweat, and the team ships features without thinking about infrastructure. Then traffic climbs. A campaign over-performs. A marketplace onboards a popular
System Design
wp_options Health Check -- Row count (healthy: 500–2000, bad: 50k+) SELECT COUNT(*) FROM wp_options; -- Autoload payload size (>1MB = problem, >3MB = serious, >10MB = broken) SELECT SUM(LENGTH(option_value)) / 1024 / 1024 AS autoload_mb FROM wp_options WHERE autoload = 'yes'; -- Biggest rows overall SELECT