System Design
The handful of ideas that stop most breaches, explained for people who do not write security code Security has a reputation for being a dark art practiced by specialists, and the deep end truly is. But the great majority of real-world breaches are not exotic. They come from a
System Design
How systems talk without waiting, and how they find things fast So far, most of the talking between parts of a system has been a direct call: one service asks another and waits for the answer. That works, but it has a weakness. The caller is stuck until the answer
System Design
What to do when one machine is no longer enough Every system starts simple enough to run on a single computer. Then it grows, more users, more data, more requests, and that one machine begins to strain. Scaling is the craft of handling that growth, and once you commit to
System Design
Keep the popular stuff close, and everything feels fast Caching is the single most common trick for making a slow system fast, and the idea is something you already do every day. You keep the things you use most within arm's reach: the coffee mug on your desk,
System Design
Where your files actually sit, and why the cloud bill is usually a storage bill Databases hold the structured records, the accounts, the orders, the messages. But a huge share of what a system keeps is not records at all. It is files: photos, videos, backups, log files, documents, machine-
System Design
Where your app's memory lives, and why this one choice shapes everything for years Every app remembers things: your account, your messages, your orders, your photos. All of that memory lives in a database. It is the most important box in almost every system diagram, and the choice
System Design
How a click crosses the world and comes back, and why "the app is slow" is usually a traffic problem When you tap a link, it feels instant. Behind that tap, your request finds an address, opens a connection, crosses the planet, gets handled, and comes all the
System Design
How software talks to software, from the first request to a payment that never double-charges Almost nothing you use is a single program. Your banking app is dozens of programs. So is your ride app, your email, the website you bought coffee filters from last night. They are built