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Built a visual editor that validates tensor shapes, counts params, estimates FLOPs/VRAM while you design. Catches incompatible residuals, mismatched Linear layers, all that before you waste GPU time. 63 ops. Proper shape inference. Exports PyTorch code that actually runs. URL- tensey.vercel.app Github- github.com/aarocy/tensey – MIT licensed. submitted by /u/uselessfuh [link] [留言]

I build one small browser tool a day and write down what I learned. Day 25 was a UUID generator. What started as "make some random IDs" turned into a proper look at how the bits are laid out, and why the newer v7 format is quietly the better default for a primary key. Live tool: https://dev48v.infy.uk/solve/day25-uuid.html A UUID is just 16 bytes with a few fixed bits A UUID is a 128-bit number, written as 32 hex digits grouped 8-4-4-4-12 . That is about 3.4x10^38 possible values, which is the whole point: any machine can pick one and trust it will not clash with any other UUID minted anywhere, ever. It carries no meaning — it is an identifier, not data. The reason UUIDs exist at all is coordination. The classic database ID is 1, 2, 3... from a central counter, and that works great until you have more than one writer. Two servers, an offline mobile app, or a sharded database cannot all ask one counter for the next number without a round-trip and a lock. UUIDs sidestep that entirely: each node generates its own IDs locally, with zero coordination, and they still do not collide. A client can even create the ID before the row ever reaches the server. Version 4: 122 random bits v4 is the one most people mean by "UUID". Fill all 16 bytes with cryptographic randomness, then overwrite two small fields so tools can recognise the format: const b = new Uint8Array ( 16 ); crypto . getRandomValues ( b ); // never Math.random() b [ 6 ] = ( b [ 6 ] & 0x0f ) | 0x40 ; // version 4 b [ 8 ] = ( b [ 8 ] & 0x3f ) | 0x80 ; // variant 10xx Two things get pinned. The high nibble of byte 6 becomes 4 — that is the digit right after the second hyphen, and it is how any parser knows the scheme. The top two bits of byte 8 become 10 , which is why the 17th hex digit of almost every UUID you see is 8 , 9 , a or b . Everything else stays random: 122 bits of it. Is "random and never collides" a contradiction? The birthday paradox says collisions become likely around the square root of the space, w

The problem with a data breach is not finding evidence. It is connecting it. But let me start where I actually was: 4 AM, last day of the hackathon, staring at this in my terminal. RateLimitError: GroqException - Rate limit reached for model `llama-3.3-70b-versatile` on tokens per day (TPD): Limit 100000, Used 99787, Requested 1616. Please try again in 20m12s. Used 99,787 out of 100,000. My deployment was half done, my demo graph was empty on the server, and the free tier had 213 tokens left. The submission deadline was hours away. I had not slept. I had not eaten. My friends were asleep and I was swapping API keys like a gambler swapping chips. This post is the story of how we got there, and how it ended at 7 in the morning with the best sigh of relief I have ever taken. First, some honesty about how I got here When I joined my first WeMakeDevs hackathon, I did not believe in it. I thought it was one of those ordinary online events. Fake prizes, no follow-through, what would I even get out of it. I joined anyway, mostly out of boredom, got into the Discord, talked to people, made a few connections. I landed in the top 50. A few days later an email showed up: a free Claude Max subscription as a gift. I read it twice. I genuinely could not believe a hackathon had actually delivered something. So when this hackathon opened, I did not hesitate. I messaged my friends and said we are joining as a team this time. Three of us: me (Mehraan), Aqib, and Ubaid. The spark We spent the first evening in our group chat throwing ideas around and shooting most of them down. Then one of my friends dropped a thought that stuck: what happens after a company gets hacked? I started digging into it. The answer is honestly depressing. After a breach, the evidence is everywhere. VPN records. File access logs. The email gateway. Badge readers at the office doors. CCTV. HR notes. Anonymous tips. Each system tells one small piece of the story, and a human analyst has to stitch all of it togeth

In this full guide, you’ll learn: 📛 Why most AI browser agents fail on modern websites. 🧱 How browser fingerprinting and anti-bot systems work. ⛑️ How to build an AI browser agent using JavaScript (Node.js) that combines Gemini, Playwright , and Bright Data to browse real websites, extract live data, analyze, reason, and generate reports locally without maintaining fragile anti-bot infrastructure ourselves that breaks 5 days later. 🗃️ How to setup Bright Data production-ready browser sessions for AI agent automation without user’s assistance manually. 🪁Introduction Building unrestricted anonymous browser automation has developed far beyond writing Playwright scripts that click buttons and scrape HTML. Modern websites actively detect automated traffic using browser fingerprints , TLS signatures , IP reputation, and behavioral analysis, making reliable automation significantly more challenging than it was just a few years ago. Modern AI browser agents don’t usually fail because they’re arbitrary. Their reasoning, prompts, and planning loops are often sophisticated. The execution layer underneath is fragile. Most tutorials show how to connect an LLM to a browser, execute a few Playwright commands , and declare you’ve built an autonomous agent. await page . goto ( url ) await page . click ( selector ) await page . type ( selector , text ) In reality, you’ve ONLY automated a browser. Commercial sites don’t gauge how intelligent your agent is. They judge whether they believe your browser is genuine. Before a page even finishes loading, they inspect what your browser actually is: the TLS handshake , IP reputation, browser fingerprints, canvas and WebGL fingerprints , cookies, device characteristics, and even the rhythm of your connection. Dozens of signals are examined in the time it takes the page to start loading. If those signals don’t look authentic, your agent rarely reaches the real application. Instead, it encounters CAPTCHA challenges, verification pages, silent re

Have you ever noticed this? You explain your project to an AI chatbot, have a great conversation, then come back later... and it asks you to explain everything again. Start a new chat, and it's like meeting you for the first time. This isn't a bug. It's how most AI models work—they don't remember past conversations on their own. That's where Cognee comes in. Instead of making AI start from scratch every time, it gives AI a way to remember what matters. Why does AI forget everything? Most AI models don't have long-term memory. Every time you start a new chat, the AI only knows what you send in that conversation. It doesn't remember your previous chats, your project, or your preferences unless you provide them again. A common solution is RAG (Retrieval-Augmented Generation) . It stores your documents in a searchable database so the AI can look up relevant information when needed. RAG genuinely helps, but it only knows what sounds similar. It doesn't know "Priya" and "the payments lead" are the same person, or that this week's ticket shares a root cause with one from March. Similarity search finds neighbors — it doesn't understand relationships. That's where Cognee takes a different approach. What is Cognee? Cognee is an open-source memory layer for AI applications. Instead of making an AI start from scratch every time, Cognee helps it remember information across conversations. It can learn from your documents, files, websites, or notes and use that knowledge whenever it's needed. Unlike traditional RAG systems that mainly find similar text, Cognee also understands how different pieces of information are connected. That gives AI more accurate and meaningful answers. It's Apache-2.0, runs locally by default, and has 27k+ GitHub stars. How does it work? At a high level, the process is simple: flowchart LR A[Text, Files, URLs] --> B[remember()] B --> C[Cognee builds AI memory] C --> D[recall()] D --> E[AI answers using remembered knowledge] For example: "Alice bought a Pr

Hey developers, I've been thinking about a problem and wanted to get some feedback from the community. We have search engines like Google, Bing, and others that help us find websites through keywords. We also have directories and archives, but I haven't found a place that attempts to catalog every active website on the internet in a structured and discoverable way. So my first question is: Does a platform already exist where I can browse or search through a massive database of active websites, regardless of whether they're popular or not? The Idea Imagine a project called "Library of Websites." Instead of ranking sites primarily through SEO and search algorithms, the goal would be to build a continuously growing database of active websites across the internet. Website owners could install a small script or verification snippet on their sites, similar to how Google Search Console verification works. Once verified, the website would automatically become part of the Library of Websites database. The platform could then: Categorize websites by industry, niche, and technology. Track whether sites are still active. Allow users to browse websites like books in a library. Discover small, independent websites that search engines rarely surface. Create a searchable index of the web that focuses on discovery rather than ranking. Over time, this could become a living map of the internet, helping people explore websites they would never normally find. Does something like this already exist? What are the biggest technical challenges in building such a database? Would website owners actually be willing to install a verification script? Is there a better approach than relying on voluntary website registration? What would you personally want from a "Library of Websites" platform? I'd love to hear your thoughts, criticism, and suggestions. Thanks!

In Part 1 , we learned that building great AI applications isn't just about writing better prompts. It's about providing the right context . But that naturally leads to another question: How much context can an AI actually understand? If you've used ChatGPT, Claude, Gemini, Cursor or any AI coding assistant for a while, you've probably experienced something like this. 🤔 "Didn't I Already Tell You That?" Imagine you're debugging a production issue with an AI assistant. You start by explaining the architecture. Then you share the API flow. Then database schema. Then logs. Then stack traces. After 30 minutes of conversation, you ask: "So what's causing the bug?" Instead of giving the answer, the AI responds: "Could you share your database schema?" You stare at the screen. "I already did..." Sometimes it even forgets details from earlier in the same conversation. Naturally, people assume: The AI has bad memory. The model is unreliable. The conversation is broken. In reality, something completely different is happening. You're running into one of the most important concepts in modern AI systems: The Context Window. Understanding this concept changes how you interact with AI—and more importantly, how you build AI-powered applications. 🧠 Before We Talk About Context Windows… We first need to understand something much smaller. Tokens. Almost every AI provider mentions them. Pricing is based on them. Context windows are measured using them. Yet many developers still think: 1 token = 1 word That isn't true. 🔤 What Exactly Is a Token? A token is the basic unit of text that an AI model processes. Humans naturally read text as: Characters Words Sentences Large Language Models don't. Before text reaches the model, it's converted into smaller pieces called tokens by a tokenizer. The model never sees your original sentence. It only sees a sequence of tokens. Think of a tokenizer as a translator between humans and AI. You write English ↓ Tokenizer ↓ Sequence of Tokens ↓ LLM The toke

1:00 AM to 2:27 AM. One bug, three root causes, zero clean error messages. It started with a simple complaint: an admin sends a push notification, and the user never receives it. No crash, no red error in the console, nothing obviously broken. Just silence on the other end. That kind of bug is the most frustrating kind. Everything looks like it's working. The permission prompt shows up fine. The admin panel says "sent." And yet nothing arrives. By 1 AM, after a long day already spent on a fairly large project, this was the last thing left to fix before calling it a night. It turned into an hour and a half of tracing one silent failure into another. Layer One: The CSP Was Blocking the Fix Before It Could Even Start The first clue showed up in the browser console: a Content Security Policy violation, quietly blocking a script that OneSignal's SDK needed to complete its own initialization. The permission popup looked completely normal, so it was easy to assume the subscription step was working. It wasn't. The script that OneSignal used internally to finish setting up the subscription was being blocked by the site's own security headers. The fix was small: add the missing domain to the script-src directive. But finding it meant not trusting what the UI looked like it was doing, and instead reading the actual network requests line by line. Layer Two: "Sent" and "Delivered" Are Not the Same Thing Once the CSP was fixed, notifications appeared to send successfully. The API returned a success response, an ID was created, and the admin panel showed a "sent" confirmation. Except the user still got nothing. This turned out to be a subtler problem. OneSignal's newer API doesn't return a recipient count in that initial response, so a message could be "created" successfully by OneSignal's servers while still reaching zero actual devices. The code was treating message creation as proof of delivery, which is not the same thing at all. The fix involved polling OneSignal's delivery-s