freeCodeCamp

Hiring the right candidate starts with one time-consuming task: screening résumés. If you’ve ever posted a job opening, you know the pain of hundreds of applications in your inbox, leaving you to spend hours reviewing each résumé manually. In this ar...... read more

Modern applications rarely live in isolation. They move between laptops, staging servers, and production environments. Each environment has its own quirks, missing libraries, or slightly different configurations. This is where many “works on my machi...... read more

In the world of big data, performance isn't just about bigger clusters – it's about smarter code. Spark is deceptively simple to write but notoriously difficult to optimize, because what you write isn't what Spark executes. Between your transformatio...... read more

Feature flags are powerful tools that let you control which features are visible to users without deploying new code. They enable gradual rollouts, A/B testing, and instant feature toggles, which are all essential for modern software development. In ...... read more

Your UI doesn’t “randomly” refuse to update. In most cases, it’s rendering cached data, which is data that was saved somewhere so the app doesn’t have to do the same work again. Caching is great for performance, but it becomes a pain when you don’t r...... read more

Harvard University's CS50 is one of the most popular beginner computer science courses in the world. We just released the entire 25-hour CS50 course on the freeCodeCamp.org YouTube channel. This is the most recent version updated for 2026, with an al...... read more

The AI landscape has shifted in 2026 from passive chatbots to proactive autonomous agents, with OpenClaw leading the charge as the most viral open-source project of the year. We just posted a comprehensive introduction to OpenClaw on the freeCodeCamp...... read more

Ah, Bluetooth. The technology we all love to hate. It's like that one friend who's always just about to connect, but then... doesn't. For years, Android developers have been locked in a dramatic, often tragic, romance with Bluetooth. We've wrestled w...... read more

As Flutter applications grow beyond a single mobile app, teams quickly encounter a new class of problems. Shared business logic begins to be copied across projects. UI components drift out of sync. Fixes in one app don’t propagate cleanly to others. ...... read more

Modern systems generate huge volumes of logs. Application logs, server logs, and infrastructure logs often contain the first clues when something breaks. The problem is not a lack of data, but the effort required to read and understand it. Engineers ...... read more