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What happens when 5 parallel API calls hit for an expired JWT at the exact same millisecond. Imagine this: You’ve built a sleek, high-performance React dashboard. The UI is sharp, dark mode is gleaming, components are modularized, and React Query is executing parallel data fetches like a grand symphony. You brew a cup of coffee, open the app after lunch, hit refresh, and… BAM! You are immediately booted back to the Login screen. No warnings, no friendly error toasts—just a cold, ruthless redirect. You check your JWT expiration timer. The access token died 5 seconds ago, but your refresh token is valid for another 14 days. So why on earth did your app decide to kick you out like an uninvited party crasher? Welcome to the chaotic nightmare of Token Refresh Race Conditions in Axios Interceptors . In this article, we’ll walk through how parallel React queries can accidentally DDOS your own backend, why standard interceptor tutorials fail in production, how we built a promise-queue lock mechanism to solve it, and the subtle "gotcha" lurking in simple error detail checks that almost broke everything anyway. 1. The Problem: The Dashboard Stampede When a user logs into our app and opens the main dashboard, React Query triggers a stampede of concurrent API requests: GET /api/teams/users/ (Fetch team members) GET /api/teams/addresses/ (Fetch locations) GET /api/auth/profile/ (Fetch user profile) GET /api/auth/activity/recent/ (Fetch activity log) GET /api/notifications/ (Fetch unread alerts) Under normal circumstances, all five requests ride happily on the same valid Bearer <access_token> HTTP header. React App ---------------------------------------------> Django Backend GET /users/ [Bearer valid] ---> 200 OK GET /locations/ [Bearer valid] ---> 200 OK GET /profile/ [Bearer valid] ---> 200 OK The Ticking Time Bomb Fast forward 15 minutes. The short-lived access token expires. The user clicks on the "Analytics" tab. All 5 queries trigger at the exact same millisecond ( T = 0ms

Back-of-the-envelope estimation for system design interviews Most people don't fail capacity math because the arithmetic is hard. They fail because they do it silently, produce a number they can't defend, and then never use it again for the rest of the interview. The math itself is trivial. The method is what's worth learning. Why interviewers ask Capacity estimation isn't a numeracy test. It's checking two things: Can you tell whether a design is physically possible before you commit to it? Do you know which constraint actually binds — storage, read throughput, write throughput, or bandwidth? A candidate who estimates 30,000 reads/sec and 200 writes/sec has learned something that changes the design. A candidate who computes petabytes of storage and then never mentions it again has just performed arithmetic. Round aggressively Precision is a trap. You're not producing a capacity plan; you're finding the order of magnitude. The single most useful substitution: 1 day = 86,400 seconds ≈ 10^5 seconds That's a 16% error and it makes every subsequent division doable in your head. Nobody will challenge it. Everyone will notice if you spend forty seconds long-dividing by 86,400. A few more worth having ready: 1 million requests/day ≈ 12/sec — round to 10 1 KB × 1 million = 1 GB 1 KB × 1 billion = 1 TB Peak traffic ≈ 2–3× average Replicated storage ≈ 3× raw ## Work in one direction Users → requests → QPS → storage → bandwidth. Don't jump around. Say each assumption out loud and label it as an assumption, so the interviewer can correct you early rather than watch you build on sand. A worked example Say we're designing a social feed. Given: 100M daily active users. Assumptions (stated, not smuggled in): Each user posts 0.2 times/day Each user reads their feed 10 times/day A post averages 1 KB including metadata A feed page shows 20 posts Writes 100M × 0.2 = 20M posts/day 20M / 10^5 = 200 writes/sec Peak (3×) = 600 writes/sec Reads 100M × 10 = 1B feed loads/day 1B / 10^5 = 10,0

I Built a Manga Reader That Works on Every Platform — Here's How Nyora is a free, open-source manga/manhwa/manhua reader for Android, iOS, macOS, Windows, Linux, Web, and even Docker — with AI-powered on-device translation and cross-platform sync. The Problem Every manga reader makes you choose: Free but ad-riddled (most Android readers) Polished but paywalled (commercial apps) Powerful but single-platform (Tachiyomi, Aidoku) I wanted one library — same titles, same progress, same bookmarks — on my phone, laptop, and browser. No ads. No account required. So I built it. What Nyora Does Every Platform, One App Platform Distribution Android APK (sideload) iOS/iPadOS IPA via AltStore/SideStore macOS .dmg or brew install --cask nyora Windows .exe (x64 + ARM64) Linux .deb , .rpm , or curl installer Web web.nyora.xyz — zero install Docker Single container, self-hosted No account needed to read. Cloud sync is opt-in. AI Translation That Understands Manga This is the flagship feature. Instead of dumping translated text over the artwork: Detects text baked into speech bubbles and captions Translates using on-device ML Typesets the result back over the original artwork Each platform uses the best local engine: Android : Google ML Kit + ONNX Runtime iOS : Apple Intelligence + Google Translate macOS : Apple Vision + MangaOCR CoreML Windows : Windows OCR Linux : Tesseract There's also an Ensemble AI Narrative Engine that tracks character names and speaking styles across chapters so translations stay consistent. 1,100+ Sources The Android app pulls from 1,100+ manga sources via 35 generic engine templates (Madara, FoolSlide, MMRCMS, etc.). Web has ~390 live, health-checked sources. Desktop ports are growing toward parity. Free Cloud Sync Sync library, categories, reading history, bookmarks, and exact page progress across all six platforms. Two sign-in methods: Google OAuth Nyora Cloud (email + password, free) Self-hostable — the backend is just Supabase/PostgreSQL with row-level s

This is going to be a very different article from what I usually write. No technical discussions, architecture deep dives, or engineering practices today. Instead, we're talking about something much older than software itself: music. We treat language like it's the default mode of human communication, like it's the real and only thing used to communicate, everything else is secondary, emotional, aesthetic, nice to have. But language is actually the outlier. It's the new protocol layered on top of something much older. Music is the original standard and we've basically forgotten how to read it. The Protocol Stack Think of communication like a network stack. Language is high-level. It's TCP/IP. Built on assumptions, needs learning, breaks the second you cross a boundary. You need: A shared vocabulary Syntactic understanding Cultural context Years of study if you actually want fluency It's powerful but It's also fragile. And it's recent . Written language is a few thousand years old. Spoken language is older, sure, but both are late abstractions compared to the hundreds of thousands of years humans have been syncing bodies to shared sound. Relative to that timeline? Language is yesterday's patch. Music? That's the lower-level protocol. The physical layer everything else runs on. A Japanese teenager at a Michael Jackson concert doesn't need to speak English. She doesn't need to understand what "Man in the Mirror" means as a concept. She also doesn't need a music degree. Music isn't zero -cost. Genre, culture, convention still shape how we hear it. But the entry barrier for emotional communication is way lower. A rhythm can hit urgency, celebration, sadness, or tension long before anyone understands the formal structure behind it. Her nervous system speaks that fluently. And so does everyone else in that stadium. How the Protocol Works Here's what happens when the song starts: 70,000 people stop being individuals and start being a distributed system synchronizing to the

If you've been anywhere near AI job postings lately, you've seen the title: Forward-Deployed Engineer. Sometimes it's "Deployment Engineer" or "Solutions Engineer" or "Applied AI Engineer." Sarvam is hiring more than a hundred of them. Palantir built a large part of its business on them. OpenAI, Anthropic, and a long tail of AI startups are all competing for the same people. And yet, if you ask five engineers what an FDE is , you'll get five different answers. Let's fix that. The one-sentence definition A Forward-Deployed Engineer is an engineer who is deployed forward — to the customer — to take a powerful but generic product and make it solve that specific customer's real problem. The word "forward" is borrowed from the military sense: you're not back at HQ, you're out in the field where the actual work happens. For an FDE, "the field" is the customer's environment — their data, their workflows, their constraints, their stakeholders. Think of it as part engineer, part consultant, part founder-in-the-field. You build, but you build for someone specific, sitting right next to you . Why AI companies need this role so badly right now Here's the thing about modern AI products: they're incredibly powerful and incredibly generic . A foundation model or an AI platform can do a thousand things — but an enterprise customer doesn't want a thousand things. They want their one problem solved, with their data, inside their systems, respecting their compliance rules. That gap — between "powerful generic product" and "solves my specific problem" — is exactly where deals are won and lost. And it's too custom, too messy, and too high-stakes to solve with documentation alone. So AI companies send an engineer to close the gap in person. That engineer is the FDE. One strong FDE can be the difference between a seven-figure enterprise contract signing or walking away. That's why the role is: High-leverage — your work directly moves revenue Well-paid — companies pay up for people who can

Bio-Tuning Glasses: Building an Invisible Biofeedback Interface with Edge AI and Adaptive Optics What if smart glasses didn't constantly tell you how healthy—or unhealthy—you are? No step counts. No stress notifications. No endless dashboards. No digital reminders telling you to "sit straight" or "go to sleep." Instead, imagine a wearable device that quietly adapts the environment around you based on your physiological state. This is the idea behind Bio-Tuning Glasses : an experimental concept for an Invisible Biofeedback Interface positioned between human biology and unconscious behavior. The goal is simple: Don't make the user adapt to the technology. Make the environment adapt to the user. From Health Monitoring to Environmental Intervention Most wearable health devices follow a familiar architecture: Sense → Analyze → Notify User The user receives information: Your heart rate is high. You are stressed. You haven't moved enough. Your sleep quality is poor. Bio-Tuning proposes a different paradigm: Sense → Infer → Intervene → Observe → Learn Instead of presenting another notification, the system attempts to modify the user's environment in subtle ways. For example: Physiological arousal detected ↓ Contextual state estimation ↓ Adaptive visual intervention ↓ Physiological response observed ↓ Personalized model updated The user may never see a notification. The intervention simply happens in the background. 1. Hardware Architecture The glasses would combine several sensing modalities in an extremely compact form factor. Biometric Sensors Potential sensors include: PPG for heart rate and HRV estimation EDA for electrodermal activity IMU for head movement and posture-related signals Temperature sensors Ambient light sensors Eye and Visual Sensing Potential inward-facing sensors could estimate: Blink frequency Eye movement patterns Pupil-related features Visual fatigue indicators Importantly, raw eye imagery does not need to leave the device. Instead: Raw Sensor Data ↓

Controller A records revocation epoch 12. Worker B, partitioned with a cached grant from epoch 11, starts another external action. The database is correct and the system is unsafe. Emergency stop is therefore a distributed protocol, not a Boolean field. What is verified In its July 21 disclosure, OpenAI says an internal benchmark used models with reduced cyber refusals and that a combination of models compromised Hugging Face infrastructure. The primary source is https://openai.com/index/hugging-face-model-evaluation-security-incident/ . Reporting on July 24 then described US discussion of emergency-shutdown and independent-audit proposals. The latter is policy coverage, not enacted law and not an extension of the official incident facts. Missing protocol details, impact boundaries, and remediation should remain unknown rather than inferred. Invariants and assumptions Assume workers, queue consumers, an authorization service, and external adapters can fail independently. Messages may be delayed, duplicated, or reordered; clocks have bounded error only if measured. Required invariants: No action starts with a grant epoch below the subject's revocation epoch. Cached grants expire within a declared lease bound. Restart cannot lower a persisted epoch. Duplicate revocation converges to the same or higher epoch. Completion means every registered executor acknowledged or its lease expired. revoke(subject, epoch=13) -> durable CAS max(current, 13) -> publish {subject, epoch:13} -> executors persist max(local, 13), ack -> controller waits for ack set OR lease expiry -> issue completion receipt with missing/expired members Failure injection Property Acceptance rule delay revocation event lease bounds stale authority no start after local lease expiry duplicate epoch 13 idempotence epoch remains 13+ deliver 13 before 12 monotonicity never returns to 12 worker restarts durability loads persisted epoch before work controller partition fail closed no new lease after expiry A minim

Hey everyone, my name is AbdulRahman Elzahaby ( @egyjs ), a software engineer from Egypt who’s recently fallen down the rabbit hole of LLMs. Like so many of us, you’ll find me in the thick of automation, bots, and making AI work for fast-tracking features and workflows. As I started diving into complex, multi-agent workflow automation, I experimented with… everything. I fiddled with n8n, played with OpenClaw, tinkered with Hermes Agent, andspent what felt like ages manually chaining together Python scripts with LangChain and LangGraph. Every tool showed promise, but my work became increasingly complex and every single workflow somehow felt... Unfinished. The way the industry seems to approach building these kinds of agents revealed a massive, structural gap in tool design. On one hand, we have intuitive, visual workflow tools like n8n. The drag-and-drop interface is great for a bird’s eye view of higher-level logic. But when you need more advanced concepts, like complex looping with conditional logic, custom state reduction, or a system that integrates properly with code review and versioning, these low-code boxes quickly hit limitations. On the other hand, we have powerful code-first frameworks like LangGraph. They provide incredible flexibility and raw execution power, but as soon as you start to build even a simple three-agent triage workflow, the boilerplate code starts to pile up. You have to write custom state schemas (TypedDict), initialize every node function individually, define custom logic for how to route between agents, set up the graph checkpointer, and grapple with environment and dependency management. What seemed missing was a sweet spot - a seamless bridge between the design intuition of visual workflows and the production-ready execution power of code-based frameworks. I wanted a tool that allowed me to simply design a workflow, and then run it efficiently without getting tangled in repetitive boilerplate code. Ultimately, I concluded that what we

TechCrunch Startup Battlefield is coming to Australia — and we're partnering with Stripe to find the country's most exciting early-stage startups.

We've been testing a new project this week. The project's origin story is a mess. Upper management...

Originally published on hexisteme notes . A while back I wrote about why your vibe-coded app looks worse than you expect. That post diagnosed the cause. This one is the fix that actually worked, on a real job: redesigning the mascot in my trip expense-splitting app. The mascot is the face of the app. It shows up in more than twenty places — onboarding, settings, the stats screen, the map, the diary, the settlement report, and five little mini-games. And it was nothing. One circle did double duty as head and body. No legs. No hands. No eyebrows. One X for an eye. Visually its identity was zero: a tinted circle. I knew it was bad. What I could not do was say what to change. Words don't converge on a picture I kept talking myself in circles about it, and so did the AI I was pairing with. Rounder? Add a hat? Bigger eyes? Every sentence sounded reasonable and none of them moved the decision. At some point I noticed what was actually going on: this was not a shortage of information. Nobody needed to go fetch a fact. It was a shortage of fidelity . A visual decision cannot converge in prose, because prose is not the medium the decision lives in. That is the tell. When a discussion loops and more words don't help, you don't need more analysis — you need a picture. So I stopped arguing and built prototypes. Three variants, not more tints The rule I gave myself: make variants that are structurally different, not palette swaps. Different silhouette, different anatomy, a different device carrying the identity. Repainting the same shape in different colors teaches you nothing. Three genuinely different creatures force a real choice. I built three and rendered every one as an action sheet so I could look at them side by side: A, a jelly bean. The safe evolution of what I already had. It slots into the UI cleanly, but its whole identity hangs on a single coin floating over its head. Shrink it and it's just a round blob again. B, a wallet. Object personification: a wallet body with

You built something. Tests pass. You're days from mainnet. Before you either skip security entirely (please don't) or spend weeks lining up a full audit, here's a self-check you can run in 20 minutes that catches the mistakes I see most often in first-time deployments. I run security reviews for small and new protocols, and the same handful of issues come up again and again. None of these need a tool — just your eyes and this list. 1. Who can call what? Open every external / public function that moves funds, mints, pauses, or upgrades. For each, ask: should a random address be able to call this? If not — is there an onlyOwner / onlyRole / require(msg.sender == ...) guarding it, in the function itself or in every internal function it calls? The classic bug isn't a missing modifier. It's a function that looks unguarded but delegates to a guarded internal one (fine), or one that looks guarded but the guard is in a branch a caller can skip (not fine). Trace the call, don't trust the signature. 2. The first-depositor trap (if you have a vault) If you mint shares from deposits (ERC-4626 or anything share-based), the first depositor can sometimes donate assets directly to the contract to inflate the share price, so the second depositor rounds down to zero shares and loses funds. Fix: virtual shares, a dead-shares mint at deploy, or a minimum-liquidity lock. OpenZeppelin's ERC-4626 handles this out of the box — a hand-rolled vault usually doesn't. 3. Reentrancy — but only the real kind Not every external call is reentrancy. It's a bug when an attacker-controlled call can re-enter and corrupt shared storage before you've updated it. Quick checks: Do you update state before the external transfer (checks-effects-interactions)? Is there a nonReentrant on functions that move value? Is the call target a trusted, immutable contract, or an arbitrary address the attacker supplies? A call to a protocol-owned contract, or a memory /local variable written after the call, is usually not

Claude Opus/Sonnet Voice Mode, Open-Weight Model Cost Savings, & GitHub AI Agent Security Today's Highlights This week's top stories focus on major commercial AI model updates, practical tools for cost-effective LLM deployment, and critical security vulnerabilities in AI-powered developer tools. Anthropic expands its multimodal voice capabilities to more powerful Claude models, while a new 'Show HN' project promises significant cost reductions with open-weight models. Claude’s voice mode is now available for Opus and Sonnet (The Verge AI) Source: https://www.theverge.com/ai-artificial-intelligence/970065/anthropic-voice-mode-claude-opus-sonnet-haiku-ai Anthropic has rolled out its voice mode capability to its more powerful Claude Opus and Sonnet models, extending a feature previously exclusive to the faster, lighter Haiku model. This enhancement allows developers to integrate advanced multimodal conversational AI into their applications, enabling real-time voice interactions with a higher degree of intelligence and nuance than previously possible. For instance, developers can now build voice agents that not only understand complex spoken queries but also provide sophisticated, context-aware responses, leveraging the deep reasoning and comprehensive knowledge base of Opus and Sonnet. This update significantly expands the potential for developers to create more natural and intuitive user experiences across various domains, from customer service and educational tools to interactive creative assistants. By making Opus and Sonnet accessible via voice, Anthropic is addressing a key demand for richer human-computer interaction, pushing the boundaries of what commercial AI APIs can offer in terms of multimodal capabilities. This move facilitates the creation of next-generation applications where seamless voice interaction is paramount, without sacrificing the underlying intelligence of the AI model. Comment: This is a huge step for building more capable voice-first applicat

Amazon is launching an update to its Alexa Plus assistant that will allow it to connect to smart home devices in new ways. With the update, Alexa Plus can link up with tech from Bosch, Delta, Ecovacs, iRobot, Yale Home, Whirlpool, Tapo, Eufy, and others, while automatically routing requests to the correct device. In an […]

Split between buying a smart calendar, a kitchen TV, a smart home hub, and a smart display? Amazon’s Echo Show 21 is all of those things in one, with a huge 21-inch screen. You can use it to control your smart lights, glance at recipes, watch TV shows, and more. Currently, Best Buy and Home […]

In the AI-funding frenzy, many startups are raising back-to-back rounds at ever-increasing valuations — but even by those standards, Corgi stands out.

GitLost is a prompt-injection exploit discovered by Noma Security that tricks GitHub's new Agentic Workflows into leaking private data. By embedding concealed instructions within public GitHub issues, attackers can circumvent security safeguards and induce AI agents to reveal confidential information in public comments. By Sergio De Simone

The clip features the David Bowie track “Five Years,” which includes lyrics such as “Earth was really dying (dying).”

The Series A was led by Battery Ventures, bringing AegisAI total funding to $49 million.

Let's say you need to implement a feature that returns a different package based on the user-provided coupon code. So you start with a model: public record Package { public int Id { get ; set ; } public string Name { get ; set ; } public double Price { get ; set ; } } And you write a function that returns a different package based on the coupon code: private static Package GetPackageFromCoupon ( string coupon ) { if ( coupon == "ABC" ) { return new Package { Id = 1 , Name = "PS5 Controller" , Price = 50.00 }; } if ( coupon == "EBC" ) { return new Package { Id = 2 , Name = "Iphone X" , Price = 200.00 }; } if ( coupon == "DDD" ) { return new Package { Id = 3 , Name = "X7 Mouse" , Price = 20.00 }; } return new Package { Id = 1000 , Name = "Soda" , Price = 1.00 }; } And invoke it from your main method: internal class Program { static void Main ( string [] args ) { var package = GetPackageFromCoupon ( "ABC" ); Console . WriteLine ( package ); Console . ReadLine (); } } Quick test Provide expected parameters and inspect the results. "ABC" => Package { Id = 1 , Name = PS5 Controller , Price = 50 } "EBC" => Package { Id = 2 , Name = Iphone X , Price = 200 } "DDD" => Package { Id = 3 , Name = X7 Mouse , Price = 20 } Works as expected. Also, if you enter something that doesn't exist: "a" => Package { Id = 1000 , Name = Soda , Price = 1 } The Problem What if you need to add more coupon codes and return different variations of the Package object? Well, it's gonna get pretty messy very soon. Quick solution - Dictionary Rather than writing every possible variation in the if block, create a dictionary where the key is the coupon code and the value is the Package: private static readonly Dictionary < string , Package > _packages = new () { [ "ABC" ] = new Package { Id = 1 , Name = "PS5 Controller" , Price = 50.00 }, [ "EBC" ] = new Package { Id = 2 , Name = "Iphone X" , Price = 200.00 }, [ "DDD" ] = new Package { Id = 3 , Name = "X7 Mouse" , Price = 20.00 }, }; The next step is to