freeCodeCamp

The 2026 FinOps Roadmap: From Cost-Blind Engineer to Cloud Financial Manager

Ayobami Adejumo |
My first AWS bill was $23,000. I had been working at the company for three weeks. Nobody told me. The bill just grew quietly in the background while I was proud of the feature I shipped. A Lambda func... read more

How to Build a Production-Safe Agent Loop: From Exit Conditions to Audit Trails

Daniel Nwaneri |
In July 2025, a Claude Code recursion loop burned between 16,000 USD and 50,000 USD in five hours. There was no crash or error, just agents doing exactly what they were told, indefinitely, because nob... read more

AI Paper Review: Chain-of-Thought Prompting Elicits Reasoning in Large Language Models

Mohammed Fahd Abrah |
For the last few years, Large Language Models have been impressing researchers with their ability to generate text, answer questions, translate languages, and perform tasks they had never been explici... read more

Build a Self-Healing CI/CD Pipeline with AI

Beau Carnes |
Learn how how to build a fully autonomous, self-healing CI/CD pipeline from scratch with a new course we just posted on the freeCodeCamp.org YouTube channel. Farzeen Ali developed this course. In this... read more

Building a Website in 2026: What Matters More Than Your Tech Stack

Manish Shivanandhan |
For years, developers have debated which technology stack was best for building websites. Some preferred React. Others chose Vue, Angular, Svelte, or server-side frameworks such as Laravel and Django.... read more

How to Run Private Text-to-Speech on Your Own Hardware Using QVAC

Djibril-M🍀 |
When I was putting the final touches on QuizRope, an educational mobile app I built that uses LLMs for real-time tutoring and homework assistance, I knew the next logical step was voice. Reading text... read more

Mastra vs LangChain: Building an AI Agent Pipeline and Analyzing the Data

Shola Jegede |
A week ago, I saw this tweet: I had just shipped SupportMesh, a multi-tenant AI support platform built on Mastra, so I had opinions from production. I liked the .dowhile() loop, the typed step schem... read more

How Large-Scale Platforms Handle Millions of Daily Transactions

Manish Shivanandhan |
Every day, millions of people order food, stream videos, send messages, book rides, make payments, and shop online. Most of these actions take only a few seconds from the user's perspective. A user cl... read more

The Saga Pattern in Node.js: How to Roll Back Distributed Transactions Across Microservices

Md Tarikul Islam |
Building reliable workflows across multiple microservices is challenging. In a monolith, a database transaction can ensure that multiple operations either succeed or fail together. But once data is sp... read more

How to Build a Browser-Based PDF Crop Tool Using JavaScript

Bhavin Sheth |
PDF files often contain unwanted margins, blank spaces, scanner borders, page headers, page footers, or unnecessary content around the main document area. Cropping allows users to remove these unwante... read more