.The V8 engine speeds up JavaScript by dynamically compiling frequently run bytecode into optimized native machine code. However, if you pass inconsistent argument types to these optimized functions, V8 panics and deoptimizes back to bytecode. Keeping your functions monomorphic (single-typed) prevents this costly deoptimization loop, ensuring maximum runtime execution speed. If you’ve spent as much time digging into V8 execution flags as I have, you quickly realize that JavaScript is constantly rewriting itself under the hood. We like to think of JavaScript as a dynamically typed scripting language. But at runtime, engines like V8 are working tirelessly to turn your code into a highly optimized, statically typed powerhouse. When we violate that type stability, we pay a massive performance tax. How does the V8 engine optimize JavaScript at runtime? V8 uses a multi-tiered compilation pipeline that starts with an interpreter for fast startup times, then upgrades hot functions to optimized machine code using a JIT compiler. By tracking runtime type patterns, the engine can safely make assumptions to skip expensive dynamic lookups. When I look at V8’s execution pipeline, I see two primary systems working in tandem: Ignition (the interpreter) and TurboFan (the JIT compiler). Initially, Ignition compiles your raw JavaScript into bytecode so your app can boot instantly. As this bytecode executes, V8 allocates a data structure called a Feedback Vector for each function. Inside this vector are Feedback Slots (managed by Inline Caches, or ICs). These slots act as recorders, capturing the exact types (or "shapes") of the variables passing through your code. Once a function runs frequently enough to cross an execution threshold, V8 marks it as "hot" and hands it to TurboFan. TurboFan reads those feedback slots, assumes the types will remain identical in the future, and compiles a highly streamlined, native machine code version of that function. What happens when you pass differe

Article URL: https://github.com/Pedroshakoor/grok-build-ios Comments URL: https://news.ycombinator.com/item?id=48971999 Points: 10 # Comments: 0

Modern web applications demand responsive, non-blocking user flows. This tutorial demonstrates a production-grade implementation for handling form submissions without full-page reloads using the native Fetch API and clean async/await syntax. The Complete Source Code Create a file named app.js and drop in the following event-driven architecture: JavaScript document.getElementById('registrationForm').addEventListener('submit', async (event) => { event.preventDefault(); // 1. Stop full page reload const form = event.target; const formData = new FormData(form); const submitBtn = form.querySelector('button[type="submit"]'); const responseMessage = document.getElementById('responseMessage'); // 2. UI Feedback: Disable button during network request submitBtn.disabled = true; submitBtn.textContent = 'Processing...'; responseMessage.textContent = ''; try { // 3. Asynchronous Fetch Request const response = await fetch(form.action, { method: 'POST', body: formData, headers: { 'X-Requested-With': 'XMLHttpRequest' } }); // 4. Status Code Validation if (!response.ok) { throw new Error(`HTTP error! Status: ${response.status}`); } const result = await response.json(); // 5. Dynamic UI State Handling if (result.success) { responseMessage.style.color = '#155724'; responseMessage.textContent = result.message; form.reset(); // Clear form on success } else { responseMessage.style.color = '#721c24'; responseMessage.textContent = result.error || 'Submission failed.'; } } catch (error) { // 6. Global Error Catching responseMessage.style.color = '#721c24'; responseMessage.textContent = 'A network error occurred. Please try again.'; console.error('Submission tracking error:', error); } finally { // 7. Reset UI State Guaranteed submitBtn.disabled = false; submitBtn.textContent = 'Submit Data Securely'; } }); The Problem with Synchronous Form Lifecycles Traditional submissions trigger a synchronous navigation cycle: the browser constructs a payload, issues a full HTTP request, and replaces the

Understand anything online without leaving the page. Discussion | Link

Netflix revealed that it paid $587 million in cash for InterPositive, a startup co-founded by Ben Affleck.

This is a submission for DEV's Summer Bug Smash: Clear the Lineup powered by Sentry . Project Overview Formbricks is an open-source survey and experience management platform built with Next.js, TypeScript, React, and Tailwind CSS. It lets teams create and deploy surveys across websites, apps, and email. Developers can self-host it or use the cloud version. With over 12,000 GitHub stars and hundreds of contributors, it is one of the most actively maintained open source alternatives to Qualtrics. Bug Fix or Performance Improvement Formbricks supports custom regex validation rules on survey questions. A survey creator can set a pattern that user responses must match before they are accepted. The problem was in how that pattern was stored. The validation schema for regex pattern rules only checked that the input was a non-empty string: // Before the fix export const ZValidationRuleParamsPattern = z . object ({ pattern : z . string (). min ( 1 ), flags : z . string (). optional (), }); z.string().min(1) means "give me any string with at least one character." It does not verify that the string is actually a valid regular expression. So a survey creator could type [invalid as their pattern, the schema would accept it, it would be saved to the database, and then when a real user submitted a response, the system would try to run new RegExp("[invalid") , JavaScript would throw a SyntaxError , and the survey would crash silently at runtime. The bug never surfaced during setup. It only appeared when a real user was trying to submit a real response. Code Pull Request: github.com/Tobore005/formbricks/pull/1 Here is the fix: const isValidRegexPattern = ( pattern : string ): boolean => { try { new RegExp ( pattern ); return true ; } catch { return false ; } }; const isValidRegexFlags = ( flags : string | undefined ): boolean => { if ( flags === undefined ) return true ; try { new RegExp ( "" , flags ); return true ; } catch { return false ; } }; export const ZValidationRuleParamsPa

So I've been working on this app for a very long time now. Started off by wanting an app that separates long form notes from short form notes visually and keeps everything organized on a canvas. The app features: -Sticky notes for quick, small notes and A4 notes for long form documents -A quick mode that uses local storage to quickly open the app and jot down a thought on the canvas -A PDF export option that exports your notes into 3 custom designed PDF styles -Visual hierarchy to replicate file

Tres semanas después de publicar un sitemap dinámico que orgullosamente listaba cada perfil de miembro, Google Search Console me dijo que esos perfiles eran un error. No con un error de plano, sino con dos veredictos más callados: Soft 404 y Duplicada sin canónica seleccionada por el usuario . Esta es la historia de leer ese reporte, separar el ruido de la única señal real, y el arreglo, que fue quitar páginas del índice, no agregarlas. TL;DR El reporte "Por qué las páginas no se indexan" de Google es ~80% benigno por diseño. Aprende a triarlo o vas a perseguir fantasmas. Mis perfiles de miembros salieron marcados como Soft 404 (uno) y Duplicada sin canónica seleccionada por el usuario (otro). La misma causa raíz: el perfil público anónimo es deliberadamente flaco, un esqueleto con el username, todo lo demás es PII oculta a quien no ha iniciado sesión. Flaco + casi idéntico entre usuarios se lee como "página vacía" y "clúster de duplicados". No puedes arreglar un Soft 404 enriqueciendo una página que por contrato no tienes permitido enriquecer. Así que el arreglo es noindex,follow en la captura, más sacar las URLs del sitemap (un sitemap que lista una URL noindex es una autocontradicción que Google va a señalar). El modelo mental en una línea: una página que a propósito no tiene contenido para los visitantes anónimos no tiene nada que hacer en un índice construido para visitantes anónimos. El reporte que lo empezó todo El reporte de cobertura del índice, ordenado por número de páginas: Razón Fuente Páginas Descubierta, actualmente sin indexar Sistemas de Google 55 Duplicada sin canónica seleccionada por el usuario Sitio web 9 Página alternativa con etiqueta canónica correcta Sitio web 3 Página con redirección Sitio web 2 Rastreada, actualmente sin indexar Sistemas de Google 2 Soft 404 Sitio web 1 Excluida por etiqueta 'noindex' Sitio web 1 No encontrada (404) Sitio web 1 Bloqueada por acceso prohibido (403) Sitio web 1 Noventa y tantas URLs "sin indexar". El instint

Are AI Agent Engrams Open Source or Proprietary? The short answer: both, and the split matters. The major agent-memory engines — Mem0, Letta, Cognee, Graphiti, LangMem, and PLUR — are all Apache-2.0 or MIT licensed on GitHub. But "open source" and "open format" are not the same thing. A project can ship under Apache-2.0 while storing your memories in opaque vector blobs you cannot read, edit, or export. The real question is not whether the software is open — it usually is — but whether your memories are. This distinction separates the field into three tiers: fully open (software + format + data you own), open-core (software is open, but the hosted memory is not portable), and fully proprietary (memory baked into a model provider's infrastructure, no export at all). Why this question exists AI agents face a brutal constraint: they forget. Every new session starts blank. Every context window overflows. The fix is persistent memory — but persistent where, and in whose format? The term "engram" comes from neuroscience. Richard Semon coined it in 1904 for the physical trace a memory leaves in biological tissue (Semon, 1904; cited in Wikipedia, "Engram (neuropsychology)"). Applied to AI agents, an engram is one discrete thing an agent has learned — a correction, a preference, a procedure — stored so it survives across sessions. The question "open source or proprietary?" asks two things at once: Is the engine that stores and retrieves engrams open source? Is the format those engrams are stored in open — readable, editable, portable? Conflating the two is how vendors end up with open-source repos and locked-in data. Tier 1: Fully open — software, format, and data These projects ship under permissive licenses (Apache-2.0 or MIT) AND store memory in a format you can inspect, edit, and export. Project License Stars (Jul 2026) Memory format Data ownership PLUR Apache-2.0 ~215 Human-readable YAML engrams Yours — plain files PLUR stores each engram as a plain-text YAML entry — an

Optimizing RAG at Scale: Chunking, Retrieval, and the Bayesian Search That Cut Latency 40% How we moved from "semantic search + hope" to a measured, tunable retrieval pipeline with 95% recall@10 The RAG Reality Check Everyone ships RAG the same way: chunk by 512 tokens, embed with text-embedding-3-small , top-k=5, stuff into context. It works for demos. Then you hit production: Legal contracts: 512 tokens splits clauses mid-sentence API docs: 1000-token chunks drown signal in noise Customer tickets: Conversational context needs overlap, not fixed windows Latency: 500ms embedding + 200ms vector search + 300ms LLM = 1s+ per query We rebuilt our retrieval layer from first principles. Here's what actually moves metrics. Chunking: One Size Fits None # rag/chunking.py from abc import ABC , abstractmethod from dataclasses import dataclass @dataclass class Chunk : text : str metadata : dict token_count : int chunk_id : str class ChunkingStrategy ( ABC ): @abstractmethod def chunk ( self , document : str , metadata : dict ) -> list [ Chunk ]: ... class FixedTokenChunker ( ChunkingStrategy ): """ Baseline. Good for homogeneous content. """ def __init__ ( self , chunk_size = 512 , overlap = 50 ): self . chunk_size = chunk_size self . overlap = overlap class RecursiveChunker ( ChunkingStrategy ): """ Respects structure: markdown headers, code blocks, paragraphs. """ def __init__ ( self , separators = [ " \n ## " , " \n ### " , " \n\n " , " \n " , " " ], chunk_size = 512 ): self . separators = separators self . chunk_size = chunk_size class SemanticChunker ( ChunkingStrategy ): """ Uses embedding similarity to find natural boundaries. """ def __init__ ( self , model = " text-embedding-3-small " , threshold = 0.7 ): self . model = model self . threshold = threshold class AgenticChunker ( ChunkingStrategy ): """ LLM decides boundaries. Expensive but highest quality for complex docs. """ def __init__ ( self , model = " gpt-4o-mini " ): self . model = model Our production config by

Building Production-Grade LLM Evaluation Pipelines: From Vibes to Metrics How we replaced "looks good to me" with automated evaluation catching 92% of hallucinations before deployment The Problem: Why "Vibe Checks" Fail in Production Three months ago, our team shipped a RAG-based customer support assistant. It worked great in testing — we'd ask it questions, read the answers, and say "yeah, that looks right." Then it hit production. A customer asked about their billing cycle. The assistant confidently cited a policy that didn't exist. Another asked about API rate limits and got numbers from a competitor's documentation. By the time we caught it, 500+ users had seen hallucinated responses. The post-mortem was brutal: we had zero automated evaluation . Our test process was literally "ask 5 questions, read answers, thumbs up." What Production Evaluation Actually Needs Academic benchmarks (MMLU, HellaSwag) don't tell you if your system works for your use case. Production evaluation needs: Domain-specific judges — Your criteria, not generic "helpfulness" Speed — Evaluation must run in CI/CD, not overnight Regression detection — Know immediately when a prompt change breaks things CI/CD integration — Block merges that degrade quality Golden dataset management — Versioned, stratified, growing test cases Architecture: The Evaluation Pipeline ┌─────────────┐ ┌──────────────┐ ┌────────────────────┐ ┌──────────────┐ │ Test Cases │────▶│ LLM Under │────▶│ Judge Ensemble │────▶│ Metrics & │ │ (Golden Set)│ │ Test │ │ - Faithfulness │ │ Regression │ └─────────────┘ └──────────────┘ │ - Instruction F. │ │ Detection │ │ - JSON Schema │ └──────┬───────┘ │ - Custom LLM │ ▼ └────────────────────┘ ┌──────────────┐ │ Dashboard/ │ │ PR Comments │ └──────────────┘ Core Abstractions # eval/base.py @dataclass ( frozen = True ) class TestCase : id : str input : dict [ str , Any ] expected : dict [ str , Any ] | None = None tags : list [ str ] = field ( default_factory = list ) # ["edge-case",

When people demo "agents that automate business workflows," the demo usually ends right where the real problem begins: the moment the agent's output touches the real world. A wrong chatbot answer is annoying. A wrong official violation letter to a restaurant, sent under a county's letterhead, is a lawsuit. For the Qwen Cloud hackathon I built Inspection Autopilot, an agent that does the follow-up paperwork for a county food-safety office, on real public data: 1,333 inspections and 3,579 violation records from Clayton County, Georgia. The interesting part is not the agent. It's the governance around it, and the numbers that prove it works. Start with the receipts Before trusting an agent's judgment, test it against reality. We replayed the county's own history: 350 real (inspection, next-inspection) pairs, each triaged live by qwen-plus using only information available at the time. Facilities the agent flagged URGENT went on to fail their next real inspection 67.6% of the time. Facilities it cleared as ROUTINE failed only 21.1%, against a 48.6% base rate. The tiers are not vibes; the future agreed with them. Three design rules 1. Citations are verified in code, not vibes. The triage agent must justify every risk call by citing violation lines copied verbatim from the inspection record. The backend checks every citation against the source; anything that does not match is dropped and counted. On the committed live eval (50 inspections, 28 of them deliberately dangerous cases), the measured hallucination rate is 0.0% across 126 citations. And because a checker that never fires is indistinguishable from one that does not work, we sabotaged it: 50 forged citations injected, half invented outright, half real violation text lifted from different inspections, the forgery a lazy validator would miss. It caught 50 of 50 and preserved all 75 legitimate citations. We know the tripwire works because we set it off. 2. The log is append-only. Proposals and decisions are insert-only

Jensen Huang left Tokyo with deals spanning Japan's entire tech ecosystem.

Scan a menu, pay a bill, onboard a smart plug, and you are using a piece of technology that was never meant for any of those things. The QR code was invented in 1994, and its original job was tracking car parts on a factory floor. Understanding why it was built the way it was explains why it now shows up on nearly every connected device. Who invented the QR code The QR code was created in 1994 by a team led by engineer Masahiro Hara at Denso Wave, a subsidiary of the Toyota group in Japan. At the time, the automotive industry ran on standard one-dimensional barcodes, the striped labels still seen on grocery products. Those barcodes held very little data, usually around 20 characters, and a busy assembly line often needed a worker to scan ten different labels on a single box of components. It was slow, and it was error-prone. Hara wanted a code that could store far more information and be read much faster. His answer was to go two-dimensional: instead of encoding data only in the width of vertical bars, a QR code (short for "Quick Response") stores data across a grid of black and white squares, packing in thousands of characters in a fraction of the footprint. The board game that shaped it The most famous detail of the QR code's origin is where Hara found his design inspiration. He was reportedly playing the board game Go on a lunch break, staring at the black and white stones arranged on the grid, when the idea of encoding information in a two-dimensional matrix of light and dark cells clicked into place. The harder problem was speed. A scanner needs to find the code and figure out its orientation before it can read anything, and in a factory a label might be rotated any which way. Hara's team solved this with the three distinctive square markers in the corners of every QR code. Those "position detection patterns" use a ratio of black to white areas that almost never occurs by chance in printed material, so a scanner can instantly locate the code and work out its an

Web Accessibility for Startups: 5 Small Wins That Scale Palak jain Palak jain Palak jain Follow Oct 7 '25 Web Accessibility for Startups: 5 Small Wins That Scale # webaccessibility # webdev # frontend # startup 21 reactions 4 comments 4 min read