Articles

JSON shows up in config files, API responses, and databases. If you’ve ever opened a response in the Network tab or edited a config file, you’ve already seen it. Here we’ll cover what it is, why it’s used, and how to avoid the usual mistakes. JSON has become the default interchange format for web and mobile applications because it is lightweight, human-readable, and supported by every major language and runtime. Building a REST API, storing config, or passing data between services—a solid grasp of JSON syntax and tooling will save you from subtle bugs and integration headaches.

REST is a style for designing web APIs that use HTTP methods and URLs. You’ll see it everywhere: public APIs, internal services, and mobile backends. Here we'll stick to the core ideas and how to use them in practice. REST isn't a standard but a set of constraints and conventions that, when followed, make APIs predictable and easy to consume. Nail those and your APIs play nicely with clients, caches, and tooling.

One giant line of SQL is a pain to read and review. A few simple formatting rules turn that wall of text into something you can actually follow. We’re talking practical formatting here, not dialect deep dives. Readable SQL is easier to debug and optimize—and teams that pick one style and stick to it stop bickering over commas and spend time on logic and performance.

Regex matches patterns in text. Yeah, it looks like keyboard smash at first—but a handful of concepts gets you through most real-world use. We’ll stick to those and skip the full language reference. Once you’ve got the main symbols and ideas, you can read and write patterns for validation, search-and-replace, and log parsing without memorizing every dialect quirk.

HTTP status codes tell the client whether a request succeeded, failed, and why. They’re part of every API and web response. Below we run through the ranges and the codes you’ll see most often. Use them right and you get better caching, clearer error handling, and APIs that behave the way clients and tooling expect.

An API is how one piece of software talks to another. For most of us that means HTTP: send a request, get a response. No prior experience assumed—we’ll stick to the basics. Frontends, mobile apps, and third-party services all plug in via APIs without touching your source code; knowing how to call and test them is bread-and-butter for full-stack and backend work.