标签：#t

In the previous article , we learned that an Origin consists of three components: Scheme (Protocol) Host Port Browsers use these three components to determine whether a request is Same-Origin or Cross-Origin . Whenever a web page attempts to access resources from a different Origin, a security mechanism called CORS (Cross-Origin Resource Sharing) comes into play. 📌 Why Does a CORS Error Occur? Suppose your web application is running at: https://app.example.com Now it tries to fetch data from: https://api.example.com Although both URLs belong to example.com , their Hosts are different. That means they have different Origins. As a result, the browser treats this as a Cross-Origin request. If the destination server does not explicitly allow this Origin, the browser prevents JavaScript from accessing the response, resulting in what we commonly call a CORS Error . 💡 Important: CORS is a browser security mechanism , not a server security mechanism. ⚠️ A Common Misconception About CORS Many developers believe that a CORS error means the request never reached the server. In most cases, that's simply not true. Typically: ✅ The browser sends the request. ✅ The server receives it. ✅ The server generates and returns a response. ❌ The browser blocks JavaScript from accessing that response. In other words, the request was successful—the browser simply refuses to expose the response to your application because the CORS policy was not satisfied. This is why sending the exact same request using tools like Postman or curl usually works without any problems. Those tools are not browsers, so they do not enforce browser security policies like CORS. 📦 How Does the Server Handle CORS? To allow JavaScript to access the response, the server must include the appropriate CORS headers. The most important one is: Access-Control-Allow-Origin: https://app.example.com This header tells the browser that JavaScript running on https://app.example.com is allowed to read the response. ✅ Examples Suppos

You've written setTimeout(fn, 0) expecting it to run "immediately." It didn't. A Promise.then() you scheduled a line later ran first, and somewhere a for loop of 50,000 iterations froze your UI for a full second despite every function being "async." None of this is a bug. It's the JavaScript event loop doing exactly what it always does — you just haven't seen the mechanism yet. What you'll learn By the end of this guide you'll be able to: Explain, precisely, why microtasks (Promises) always run before macrotasks ( setTimeout , setInterval ) — even at a zero delay Predict the exact console output order of any mix of synchronous code, setTimeout , and await Diagnose a frozen UI as a blocked call stack, not a "slow async function" Choose correctly between queueMicrotask , setTimeout(fn, 0) , and requestAnimationFrame for a given timing need Avoid the two most common event-loop bugs: microtask starvation and accidental serial await s in a loop Who this is for: you've written async / await and used setTimeout , but you want the model that makes their interaction predictable instead of memorized. Contents Why the JavaScript event loop exists The mental model Stage 1: the call stack and blocking code Stage 2: Web APIs and the macrotask queue Stage 3: Promises and the microtask queue Stage 4: async/await is sugar, not magic Stage 5: rendering, and Node's extra queues Edge cases and gotchas Best practices FAQ Cheat sheet Key takeaways Why the JavaScript event loop exists JavaScript runs on a single thread. One call stack, one thing executing at a time, no parallel function calls in the same realm. That's a deliberate design — it means you never need locks or mutexes to protect a shared variable — but it creates an obvious problem: how does a single-threaded language do anything concurrent, like waiting on a network response, without freezing the entire page while it waits? Here's the naive expectation, and why it would be a disaster if JavaScript worked this way: console . l

Imagine you're loading a dashboard. Four widgets, four APIs, fire them all at once: const [ users , revenue , alerts , activity ] = await Promise . all ([ fetchUsers (), fetchRevenue (), fetchAlerts (), fetchActivity (), ]); The alerts API is occasionally slow and sometimes returns a 500. When it does, your entire dashboard fails. Not one broken widget — four broken widgets. Promise.all rejects on the first failure and takes the other three successful results with it into the void. You reached for the right primitive for concurrency, but the wrong one for this use case. The four methods and what they actually do JavaScript gives you four ways to run promises concurrently. They differ in one thing: what happens when a promise fails or resolves first. Method Resolves when Rejects when Promise.all All succeed Any one fails Promise.allSettled All finish (success or failure) Never Promise.any Any one succeeds All fail Promise.race Any one finishes Any one fails first The instinct to reach for Promise.all is understandable — it returns all the values in a single array and feels like the obvious way to "do these things at the same time." But concurrency and failure handling are two separate questions. Promise.all answers both at once, and the answer to the second one is often wrong for the situation you're in. 🎮 Try it yourself ▶️ Open the interactive playground → Runs right in your browser — poke at it and watch the concept react live. Promise.allSettled — partial success Promise.allSettled waits for every promise to settle — resolve or reject — and returns a result array describing what happened to each one: const results = await Promise . allSettled ([ fetchUsers (), fetchRevenue (), fetchAlerts (), fetchActivity (), ]); for ( const result of results ) { if ( result . status === ' fulfilled ' ) { console . log ( ' got data: ' , result . value ); } else { console . error ( ' failed: ' , result . reason ); } } Each element has a status of 'fulfilled' (with a value ) or 'r

Every developer I know has the same reflex now. Hit an unfamiliar concept, paste it into ChatGPT, read the explanation, move on. I did this for months. It felt efficient. Then I noticed a pattern: I was reading a lot of clear explanations and retaining almost none of them. I could follow along perfectly in the moment and then draw a blank a week later when I actually needed the knowledge. The problem was not ChatGPT. The problem was using a general-purpose conversational tool for a job it was never designed to do. Here is what I switched to, and why it works better. The three failure modes of using a chatbot to learn Passive consumption feels like learning. Reading a good explanation triggers the feeling of understanding without the work that creates actual memory. You nod along, it makes sense, and nothing sticks. This is the biggest trap. There is no retrieval practice. The research on this is well established: you remember things by pulling them out of memory, not by putting them in repeatedly. A chatbot will explain the same concept ten different ways, but it will never make you answer a question you cannot immediately answer. That struggle is the mechanism. Confident hallucination is dangerous when you are the beginner. If you already know a topic, you can spot when an AI is subtly wrong. If you are learning it for the first time, you cannot, and you may internalize something incorrect with full confidence. For technical material, this is a real cost. What actually works better Tools that quiz you. Anything built around retrieval practice and spaced repetition beats passive reading by a wide margin. If a tool generates questions from your material and makes you answer them over spaced intervals, it is working with how memory actually forms rather than against it. Tools that read YOUR source material. This one is huge for technical learning. Instead of asking a model to answer from its general training data (which may be outdated or wrong for your specific libra

Module caching, execution order, and circular imports explained by tracing what actually happens. How Python's Import System Works and Why It Matters for Debugging The import system is one of the least understood parts of Python and one of the most practically important for debugging production issues. Circular import errors, unexpected code execution, and module state bugs all stem from not understanding what happens when Python encounters an import statement. What Happens on the First Import When Python executes import mymodule for the first time: Python checks sys.modules for mymodule . If found, returns the cached module object immediately. If not found, Python locates the module file. Python creates a new module object and adds it to sys.modules under the module name. Python executes the module file's code in the new module's namespace. The name mymodule in the importing module is bound to the module object. Step 3 happens before step 4. This is critical for understanding circular imports. The Module Cache import sys import os print ( " os " in sys . modules ) print ( sys . modules [ " os " ] is os ) Output: True True Every imported module is cached in sys.modules . Subsequent imports return the cached object without re-executing the module code. Module-Level Code Executes on Import # config.py print ( " config module loading " ) DEBUG = True print ( f " DEBUG is { DEBUG } " ) # main.py import config import config # second import print ( config . DEBUG ) Output: config module loading DEBUG is True True The print statements in config.py run exactly once — when the module is first imported. The second import returns the cached module object without re-executing the code. Circular Import Behavior # module_a.py print ( " loading module_a " ) from module_b import b_function def a_function (): return " from a " # module_b.py print ( " loading module_b " ) from module_a import a_function def b_function (): return " from b " When you import module_a , Python starts exe

Originally published at woitzik.dev A previous article here covered setting up gitleaks for homelab secret scanning - the setup, the pre-commit hook, getting CI to fail on new commits that contain secrets. The setup was correct. The tool was running. The CI was green. And it had been quietly suppressing a live production credential for months. This is the follow-on story: not about getting gitleaks running, but about the specific way a baseline file breaks the guarantees you think you have once it's in place. View the complete homelab infrastructure source on GitHub 🐙 What a Baseline File Does (and Is Supposed to Do) When gitleaks first runs on an existing repo, it finds every secret-shaped string in the full git history - including secrets that were introduced years ago, rotated long since, and are completely inert. Flagging those in CI creates noise that causes developers to tune out gitleaks entirely, which is worse than not having it. The baseline workflow is the standard answer: run gitleaks on the current state, export all findings to a JSON file, commit that file to the repo, and tell gitleaks to suppress any finding that already appears in the baseline. Future commits that introduce new secrets still fail; old known-inert findings don't. # Generate baseline from current HEAD gitleaks detect --report-format json --report-path .gitleaks-baseline.json # Tell gitleaks to use it gitleaks detect --baseline-path .gitleaks-baseline.json The assumption embedded in this workflow: findings that appear in the baseline are inert. They were there before the baseline was generated; they've been there; they're known. The Assumption That Broke It The baseline was generated at a point when the repo contained Garage's rpc_secret and admin_token committed in a YAML file. Those were real production values - the cluster was live, using those exact secrets - but the baseline suppression treated them as "known, reviewed, not a problem." The commit that introduced them had happened

Responsibly dispose of your food scraps with one of these indoor, (mostly) odor-free, WIRED-tested devices.

The European Union is weighing sweeping new restrictions on children's and teenagers' access to social media, including age limits, an outright ban, and phased access. Social media platforms could also be forced to prove their services are not harmful before young people are allowed to use them. European Commission President Ursula von der Leyen said […]

Most people assume better AI performance means a bigger bill. That assumption is quietly being proven wrong. The "Don't Touch It" Trap in AI Products There's a psychological pattern that shows up in almost every team running a live AI-powered product: once something works, nobody wants to mess with it. And honestly, that instinct makes sense. You've tuned your prompts, worked out the edge cases, trained your users, and finally gotten the thing stable. The idea of swapping out the underlying model - the engine of the whole operation - feels like pulling a thread that might unravel everything. So teams stay put. They watch new model releases come out, read the benchmark comparisons, and quietly decide it's not worth the risk. The phrase you hear most often is "if it ain't broke, don't fix it." The problem is that this logic made sense when model upgrades were expensive and disruptive. That's no longer the default reality. What's actually happening now is that AI providers are competing hard on price-per-token while simultaneously improving quality. That combination - better output, lower cost - breaks the old mental model most product people are still operating with. What a Model Migration Actually Involves Let's be clear: switching AI models isn't a one-click operation. But it's also not the months-long project many teams imagine it to be. At its core, a model migration for an AI agent involves three things: re-evaluating your prompts (because different models respond differently to the same instructions), running parallel tests to compare output quality on your real use cases, and updating any API parameters that differ between versions. That's the actual work. For most small-to-medium deployments, that's days of effort, not weeks. The bigger shift is in how you think about model versions. Rather than treating the model as permanent infrastructure, it helps to think of it more like a dependency in your software stack - something you update deliberately, test careful

If you have ever logged into a corporate computer, searched for a colleague in your company’s email directory, or used a single set of credentials to access dozens of different internal applications, you have likely interacted with LDAP . Standing for Lightweight Directory Access Protocol , LDAP is an open, vendor-neutral, industry-standard application protocol for accessing and maintaining distributed directory information services over an IP network. In simpler terms, it is the underlying language that allows different systems and applications to communicate with a central directory to find information about users, devices, and permissions. Think of LDAP as a highly organized, digital phonebook. When an application needs to know if "John Doe" is a valid user and what his password is, it uses LDAP to ask the phonebook. How LDAP Organizes Data Unlike traditional relational databases (like SQL) that store data in tables, LDAP stores data in a hierarchical, tree-like structure known as the Directory Information Tree (DIT) . This makes it incredibly fast at reading and searching for information, which is exactly what an authentication system needs to do millions of times a day. Here are the core components of this structure: Root: The top level of the directory tree, usually representing the organization (e.g., dc=example, dc=com ). Branches (Organizational Units - OU): Categories or departments within the organization (e.g., ou=Marketing , ou=Servers ). Leaves (Entries): The actual objects being stored, such as a specific user, printer, or computer. Attributes: The specific pieces of data tied to an entry. For a user entry, attributes might include givenName (first name), mail (email address), and userPassword . Every entry in an LDAP directory has a unique identifier called a Distinguished Name (DN) . It acts like an absolute file path. For example, John Doe’s DN might look like this: cn=John Doe, ou=Marketing, dc=example, dc=com How Applications Talk to LDAP When an

Like Google Maps, Waze is going all-in on Gemini.

Waze is getting an AI makeover. Google is integrating its flagship AI assistant, Gemini, into the driving app with the goal of letting users personalize their trips a little more. Of the four new updates, only two are being described as involving Gemini. Waze says its updating its conversation reporting feature, first introduced in 2024, […]

Local-first AI video editor for Mac Discussion | Link

Jake Lazaroff discussed the AT Protocol as a framework for distributed applications beyond social networking. He emphasised a local-first architecture where users maintain data in PDSs while leveraging shared infrastructure for synchronisation and updates. The presentation included experiments showcasing collaborative tools and highlighted the benefits of reduced reliance on app-specific backends. By Olimpiu Pop

The AI-native Operating System for founders. Discussion | Link

There is a kind of loneliness that does not always announce itself. It can be quiet. Heavy. Hidden behind a smile. It can make someone feel as though no one truly understands what they are carrying. Dear Stranger was created for those moments. It is a place where someone can pause. Breathe. Read. Feel less alone. And maybe, just maybe, carry a little more hope than they came with. This is not just a project to me. It is a quiet promise. A small place I built with my heart. A space where words can travel gently across distance and still carry comfort. I built Dear Stranger because I believe that even the smallest page can hold something powerful: hope, clarity, warmth, and the feeling of being understood. What I Built Dear Stranger is a web experience designed to feel intimate, human, and deeply personal. It is a space where someone can open a page written by a stranger, read something honest, and feel, even for a moment, that they are not alone. The project is built like a book made of feelings. It invites the visitor to step into a calm, reflective experience where words matter more than noise. They can read pages that speak to comfort, strength, peace, and hope. They can save what touches them. They can leave behind their own words for someone else to find one day. It was never meant to be just another website. It was meant to feel like a page that was waiting for you. Demo The experience is best felt by opening it and letting it meet you where you are. It is meant to be soft, reflective, and quietly powerful. Dear Stranger - this is for you. Code The project is built with Next.js and designed as a personal, story-like interface where emotion is part of the experience. The structure allows users to move through a reading journey, interact with meaningful content, and leave behind something sincere. Konarksharma13 / Dear-Stranger Dear Stranger — A Page for You This website was never meant to be just another page on the internet. It is a quiet place made for the hea

Most people think building an AI voice agent means writing a clever prompt. I build these for a living, and I can tell you the prompt is maybe an hour of the work. The other week disappears into two places: wiring up everything the agent touches, and testing it against the twenty ways a real caller will break it. So I built a pipeline that points one AI coding tool at each of those problems. Claude Code generates and wires the agent from a spec. Comet, an AI browser automation tool, runs it through dozens of messy call scenarios before a human ever picks up the phone. This post is how that loop actually works, and where it still needs me. Why the build loop is slow (and it is not the prompt) When you picture building a voice agent, you picture the prompt. That is the easy part. The slow part is everything around it. A production agent for, say, a car garage is not one artifact. It is a conversation flow, a set of custom functions that hit your automation layer, calendar and CRM wiring, a telephony number with A2P registration, and a pile of edge-case handling that only shows up when someone calls in angry with a dog barking in the background. The reason it is slow is not typing. It is the round trips. You build a version, you call it, it fumbles when the caller interrupts or asks something off-script, you fix one thing, you call it again. Each loop is a few minutes of manual dialing and listening. Multiply that by the fifty scenarios a real agent needs to survive and you have burned a week. The pipeline exists to kill those round trips. Half one: Claude Code builds the agent from a spec The first insight is that most of what goes into a voice agent is structured and repetitive, which is exactly what an AI coding tool is good at. I do not hand-write every custom function and every n8n node from scratch for each new client. I write a spec, and I let Claude Code turn that spec into concrete artifacts. The spec is a plain description of the vertical and the business: wh

Videos are one of the heaviest assets you can add to a web page. Loading videos too early can significantly impact your application's performance. The good news is that modern browsers are starting to support lazy loading for video elements , allowing you to defer loading until users are likely to watch them. However, there's one important thing to know: 👉 This feature is not yet part of the Baseline web platform , so browser support is still limited. At the time of writing, lazy loading for <video> elements is supported in Chromium-based browsers such as Google Chrome , Microsoft Edge , and Opera , while browsers like Firefox and Safari do not yet support it natively. In this article, we'll explore: What lazy loading videos is Why it's important for web performance How to implement it Browser support considerations Best practices for optimizing video loading Let's dive in. 🤔 What Is Lazy Loading for Videos? Lazy loading means delaying the loading of a resource until it's actually needed. Instead of downloading every video immediately during page load, the browser waits until the video is close to entering the viewport. This helps reduce: initial network requests bandwidth usage page load time memory consumption Especially on pages with multiple videos, the difference can be significant. 🟢 What Problem Does It Solve? Imagine an e-commerce page with several product videos. Without lazy loading: every video starts downloading immediately bandwidth is consumed even for videos users never watch page rendering may become slower This negatively impacts; Largest Contentful Paint (LCP), Time to Interactive (TTI), and overall user experience. Most visitors won't watch every video on the page. So why load them all? Lazy loading ensures videos are fetched only when they're actually needed. 🟢 How to Lazy Load a Video The easiest approach is using the loading="lazy" attribute. Example: <video controls loading= "lazy" poster= "/preview.jpg" > <source src= "/video.mp4" type= "vide

Multiple Tailscale tailnets at once, no switching + no VM Discussion | Link

Try the demo: K-Saju Crew For fun only. K-Saju is an entertainment project. The K-Pop roles below are a playful interpretation of saju-inspired signals, not personality assessment or advice. A two-person compatibility page can stay stateless with almost no effort. Put both birth dates in a URL, render the result on the server, and the link is the record. No account, no database, no cleanup job. That was already a product rule in K-Saju. We do not retain personal inputs. A result is reproducible from its GET parameters. Then we built /crew : “What if your friend group debuted as a K-Pop group?” A creator makes a link, sends it to a group chat, and each friend enters their own birth date. At three to seven members, the app assigns distinct positions, shows pairwise chemistry, and creates a shareable poster. The fun part is the casting. The engineering problem is that the social flow needs a temporary shared state. A link cannot accumulate submissions by itself. This post is about the decisions behind that feature: where we allowed state, how we made the result durable without retaining a lobby forever, and how we kept the casting explainable instead of treating it as a black-box score. The conflict: a self-service group flow needs somewhere to collect data There were two clean but incomplete options. The first was to keep everything stateless. The creator would enter all members' dates at once, then receive a result URL. It matched our existing architecture, but it defeated the point of sharing a link. The person who starts the group often does not know everyone else's date, and asking them to collect it in a chat creates friction before the feature has started. The second was a conventional persistent group object. It would make joining easy, but it would turn a deliberately stateless service into one that keeps user-provided dates indefinitely unless we built retention and deletion policies around it. We chose a hybrid instead: The lobby is temporary state. It store