Long-form tutorials and news from one of the biggest learn-to-code communities.
In this tutorial, I'll show you how to build a multi-agent AI system in Python with no orchestration framework. We'll also implement this in LangGraph with nodes, edges, and shared state. The point of
If you've been building Node.js projects, you've probably had an experience like this. The project runs fine on your machine, but when you push it to a server, something breaks. Maybe it's a different
The Android Bluetooth stack spent about a decade being the reason your headphones disconnected during the good part of a song. Gabeldorsche is Google's attempt to fix that at the architectural level,
When a CEO buys shares after their company’s stock has fallen hard, it's tempting to read the purchase as a vote of confidence. The person running the business knows more than the average investor, so
A Live Activity is the card that sits on your lock screen while a delivery rider approaches, updating itself without you opening the app. Apple shipped the API in iOS 16.1. Google shipped its own vers
Okay, pop quiz: What is a neural network? What is deep learning? Does anything come to mind? I know that feeling – yes, that thing you’re feeling now. It’s either confidence that you know what I’m ask
Most AI agents are reactive as they wait for us to ask something. In this tutorial, I'll show you how to build local AI assistants that run on a schedule, handle the tasks you care about, and generate
Generative AI agents are transforming .NET development by helping developers automate repetitive coding tasks, generate unit tests, assist with debugging, document code, and accelerate CI/CD workflows
A Sheet is a panel that slides in from the edge of the screen instead of popping up in the center like a modal. You've likely used one when you've opened a shopping cart on an e-commerce site or tappe
PDF files are widely used for sharing documents because they preserve formatting across different devices. Many PDFs contain valuable images such as logos, product photos, charts, diagrams, illustrati
A Postman collection is a great place to explore an API. But it's a poor place to keep your tests. Most teams find this out the slow way. Someone exports the collection, converts the requests into tes
The first time I built an API without thinking about roles, I gave every logged-in user the same access. It worked fine until a regular user accidentally hit a delete endpoint and wiped test data. Tha
Not every PDF contains searchable or editable text. Many PDFs are simply scanned images of documents such as invoices, contracts, books, receipts, government forms, and handwritten notes. While these
PDF files are one of the most widely used document formats for sharing reports, invoices, contracts, books, research papers, manuals, forms, and business documents. Although viewing a PDF is simple, u
Add a product to a Shopify store the default way and the whole page reloads. The shopper is looking at your product, they click Add to cart, and the browser throws the page away and rebuilds it. On a
Managing dates and times in JavaScript is notoriously tricky, often leading to subtle bugs that only surface once an application hits production. To help you master this fundamental skill, the freeCod
Picture this: you hit an API endpoint, and you get an API response back. You pass the data straight into your application, and everything looks fine in development. Your mock data is clean, your types
Adding margins to a PDF is a common task when preparing documents for printing, binding, archiving, or sharing professionally. While many PDF editors include this feature, they often require installin
Have you ever tried to spot the differences between two long paragraphs of text? Reading line-by-line to find a missing word or a new sentence is a massive headache. In this tutorial, you'll build you
PDF documents come in many different page sizes. Some are designed for A4 paper, while others use Letter, Legal, Tabloid, or custom dimensions. This can create problems when printing, sharing, archivi
Imagine opening your laptop and writing code that follows the laws of Quantum Physics. Sounds like science fiction, right? That's exactly what I thought the first time I heard about quantum computing.
A Bloom filter gives you something that feels like magic: it can tell you whether an item is in a set of billions, using only a few kilobytes of memory. And it answers in the same tiny amount of time
In this tutorial, I’ll show you how to build an AI web research agent using Ollama, Qwen, and Python. The agent searches the web for a topic, fetches relevant pages, and uses a local LLM to generate a
PDF files are often created by combining scans, exporting documents from different systems, or processing large batches of pages. In many cases, the final PDF ends up with pages arranged in the wrong
Most security problems I've shipped in my career weren't exotic. They weren't nation-state attacks or clever zero-days. They were boring. A missing limit here, a forgotten timeout there, a string comp
Large Language Models have fundamentally changed how we build internal business applications. They allow developers to create intelligent software that can answer questions, synthesize complex enterpr
On June 12, 2026, SPY closed up 0.54%. EchoStar (SATS) dropped 11%. Lennar (LEN) dropped 4.9%. Most of the other 500 stocks in the index barely moved beyond what SPY’s own gain would predict. That gap
Typically, when we start experimenting with AI, many of us begin similarly. We try a single LLM call as the core of an app, like this: const response = await llm.chat("Explain Kubernetes"); For a lit
Many AI Agent tutorials propose the same fix for bad output: reflection. Your agent generates garbage JSON? Just add another LLM call to "review" it. The second call critiques the first, the first tri
Performance tools are good at showing you what's slow. They can tell you that your Largest Contentful Paint is 4.2 seconds, your JavaScript bundle is too large, or an image below the fold is loading t
Your browser remembers every page you've ever opened, but it has no idea why you opened any of them. You might spend three days comparing laptops across a dozen tabs, get distracted, come back a week
Most financial models use analyst consensus as a single forward-looking input: revenue estimate, EPS estimate, EBITDA estimate, or some version of a forward margin assumption. That works, but it flatt
Retrieval-augmented generation, or RAG, is a pattern where an application retrieves relevant source material and adds it to a model prompt so the model can answer from that context. A larger context w
Lately, there's been more focus on creating specialized Small Language Models (SLMs) for high-throughput, real-time applications. But we seem to be at an impasse: we excel at fine-tuning these models,
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
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.
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
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
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
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
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
On April 3, 2025, the US announced sweeping tariffs on Chinese imports. SPY dropped 4.8% that day. The next day, it dropped another 6%. Financial news ran the usual headline: markets rattled by geopol
If you're looking to level up your front-end development skills by building a practical web utility, this is the guide for you. We'll code a fully functional Case Converter Tool from scratch using onl
Dart backend frameworks exist on a spectrum. At the minimal end sits Shelf, with raw primitives and full control. You wire everything yourself. At the maximal end sits Serverpod. It's a full framework
Your first scaling problem rarely arrives with a bang. For a while, everything is fine: pages load fast, the database barely breaks a sweat, and the team ships features without thinking much about inf
PDF files contain more information than what appears on the page. Behind every PDF document is metadata that stores information such as the document title, author, subject, keywords, creator applicati
Every application that handles user data eventually hits the same problem: not all users should see the same things. A junior nurse should not be able to access every patient record in the hospital. A
Modern payment systems look simple from the outside. A user clicks a button, enters payment details, and money moves from one account to another. But once payments happen repeatedly rather than once,
Working with healthcare data introduces preprocessing challenges that go beyond those you might encounter with structured data. Some familiar techniques still apply, while others look very different o
According to the Stack overflow technology survey in 2025, JavaScript is one of the most widely used programming languages in the world. We use it to build frontend applications, backend services, pay
PDFs are still one of the most widely used document formats in business. Financial reports, invoices, contracts, compliance filings, and operational documents are often shared as PDFs because they pre
PDF files often become difficult to manage when pages are out of order, scanned incorrectly, duplicated, or spread across multiple documents. Instead of manually recreating the document, users often n
The AI capex trade is usually discussed like one clean idea. Capex simply means capital expenditure, or the money companies spend on long-term assets like data centers, chips, servers, power systems,
When you're working with contracts, reports, invoices, manuals, or academic documents, page numbers make navigation much easier. Instead of manually editing every page, modern JavaScript libraries let
Web scraping has evolved. If you’ve ever tried to pull data from a site, only to be hit with a CAPTCHA, an IP ban, or a "403 Forbidden" error, you know that modern websites are built to block automate
Master the transition from simple prototypes to production-grade RAG systems by addressing the critical scaling, debugging, and security challenges that standard tutorials often ignore. We just posted
Automation scripts often validate process completion instead of system health. A Kubernetes pod can be running while the application inside it can't authenticate to the database. A Terraform deploymen
Sometimes PDF pages appear upside down, sideways, or in the wrong orientation after scanning or exporting documents. Instead of re-creating the document manually, users usually just need a quick way t
Most developers learn JavaScript by memorizing rules and copying framework patterns. But when a weird production bug hits or a senior engineer asks a deep architectural question during an interview, s
PDF watermarks are commonly used for branding, document protection, approvals, confidential files, and internal document tracking. Whether it’s adding a company logo, a “CONFIDENTIAL” label, or a draf
Real-world time series data is rarely clean. Sensors drop out, systems clock-drift, pipelines duplicate records, and manual data entry introduces mistakes. By the time a dataset reaches your notebook,
In this tutorial, you'll learn how to create a simple arithmetic calculator in Python with Tkinter. The project will be one of your first steps towards building an actual GUI in Python. This is a hand
When I started studying OSINT, I always felt I was just putting random values into software without deeply understanding what I was doing. After months in the field, I realized I wasn't really investi
Whether it’s invoices, scanned documents, reports, certificates, or receipts, users often need to convert PDF pages into image files quickly. Modern browsers make this much easier than before. Instead
Since moving to Silicon Valley in 2025, I've seen AI everywhere. And after I attended NVIDIA GTC 2025, one thing became very clear from many conversations I had: most companies now have AI agents runn
Whether it’s scanned documents, screenshots, receipts, notes, certificates, or multiple photos, users often need a quick way to combine images into a downloadable PDF. Modern browsers make this much e
Live options analytics change constantly. Implied volatility shifts, Greeks drift, and the shape of the surface can look different even a few minutes later. But a lot of teams still treat these number
Most financial AI tools are good at one thing: summarizing a stock. You ask about Apple, NVIDIA, or Tesla, and they give you a clean overview of price action, a few ratios, and maybe some company cont
If you've built a Django API and you're wondering how to add authentication so that each user can only access their own data, you're in the right place. Most Django tutorials teach you session-based a
JavaScript is famously single-threaded, yet it powers highly complex, interactive web applications without freezing up. How is this possible? The answer lies in the Event Loop. The Event Loop is a cor
PDF files are everywhere. From invoices and reports to résumés and documents, they’re one of the most common file formats we deal with. But there’s a common problem: PDFs can get large quickly. If you
Working with PDFs is part of everyday development. Sometimes you don’t need the entire document. You just need a few pages — maybe a specific section, a report summary, or selected invoice pages. Most
Most full-stack React tutorials stop at "Hello World." They show you how to render a component, maybe fetch some data, and call it a day. But when you sit down to build a real SaaS application, you im
Modern web applications increasingly need to evolve faster than a single team can maintain a monolithic codebase. Product teams often want to add features independently, experiment with new capabiliti
By Scott Gary React is a highly popular and powerful JavaScript library for user interface development. Its component-based architecture, combined with its declarative nature, is one of the primary re…
In React, data is typically passed down from parent to child via props. But this can lead to "prop drilling" – where we have to pass props down through lots of components to get them where they're nee…
React provides various hooks that make it easier to manage application state and other React features in functional components. Hooks provide class component features to functional components, and the…
Recently, I was trying to upgrade some of my open source projects. They were made using create-react-app around 2019, and I wanted to upgrade to a newer version of NodeJS and Jest. This would let me t…
How can you keep track of the number of times a user clicks a button? How are the hearts on Instagram or the likes on Facebook counted? In this tutorial, we will build a button that tracks the number…
In complex React applications, managing application state effectively can become a challenge. This is where Redux, a predictable state management library, steps in. By introducing a unidirectional dat…
React 19 introduces Actions, which are asynchronous functions. Actions are helpful in making form submissions easier. This tutorial dives into what Actions are and how to use them. You'll learn about:…
Hi fellow developers! Have you ever wondered how social media apps like Facebook and Instagram keep you scrolling endlessly through your feed? This user experience, designed to load new content on dem…
Validation is a key part of development, regardless of what programming language you’re writing. Developers should always be validating user input, API parameters, and retrieved values. One of the mos…
In React.js, managing form inputs and user interactions is a crucial part of building dynamic web applications. Two key concepts that developers need to understand are controlled and uncontrolled com…
The web has evolved from rigid color coding and 2D rendering to an era of complex, aesthetically pleasing animations and 3D rendering options. There have also been integrations with new technologies,…
Animations are what make plain websites turn into exciting and unforgettable experiences. They give your website a bit of personality and uniqueness and leave the visitor admiring the overall aestheti…
