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The potential deal highlights a growing trend of complex, multi-stage funding rounds that mask true entry prices.

"Missiles are being launched at the joint force every single day in [Operation] Epic Fury."

The US is home to some of the most polluted air on the planet as smoke from 120 out-of-control Canadian wildfires drifts across the border.

Pebble founder Eric Migicovsky says buyers of its new e-paper smartwatches should know what they're signing up for and trust Pebble to make things right if they run into issues, despite the short warranty. "I think the most important thing is trust," Migicovsky told me in an interview this week. "Do people trust the product […]

The NHTSA recently called for autonomous vehicle companies to improve how cars respond in emergency situations.

Installing Apache Kafka 4.2 on Ubuntu 24.04 (WSL2) Using KRaft Mode: A Complete Step-by-Step Guide Learn how to install Apache Kafka 4.2 in KRaft mode, understand its architecture, create topics, produce and consume messages, and troubleshoot common configuration issues—all without ZooKeeper. 🚀 Introduction Apache Kafka has become the de facto standard for building event-driven , real-time , and high-throughput applications. Whether you're processing millions of financial transactions, collecting application logs, streaming IoT sensor data, or connecting microservices, Kafka provides a scalable and reliable messaging platform. Until recently, setting up Kafka required running Apache ZooKeeper alongside Kafka brokers. While powerful, ZooKeeper added operational complexity and introduced another distributed system that administrators had to manage. Beginning with recent Kafka releases, KRaft (Kafka Raft Metadata mode) removes this dependency by allowing Kafka to manage its own metadata internally. This makes installation simpler, reduces operational overhead, and improves scalability. In this guide, we'll install Apache Kafka 4.2 on Ubuntu 24.04.4 LTS (WSL2) , configure a single-node KRaft cluster, and walk through the complete lifecycle: Installing Kafka Understanding the Kafka architecture Configuring KRaft mode Starting the broker Creating topics Producing and consuming messages Troubleshooting common issues Understanding the purpose of each configuration parameter Rather than simply listing commands, I'll explain why each step is necessary so that you understand how Kafka works under the hood. What is Apache Kafka? Apache Kafka is a distributed event streaming platform designed to move data reliably and efficiently between applications. Instead of applications communicating directly with each other, they communicate through Kafka. A producing application writes messages to Kafka. Kafka stores those messages reliably. One or more consuming applications read those m

"We're turning the clock back on rational healthcare."

After the browser transfers a file, the server may still scan, transcode, extract metadata, or generate previews. The interface needs status updates, but the most fashionable real-time transport is not automatically the most reliable choice for an event guest on a mobile browser. Start with the update contract Define states and transitions before choosing transport: accepted -> queued -> processing -> ready accepted -> rejected processing -> processing_error Every status response should include a monotonically increasing version or timestamp. The client can ignore events older than the state it already knows. Polling is a strong baseline HTTP polling works through proxies, resumes naturally after a page wake, and is easy to cache and rate-limit. Use adaptive intervals: one second just after acceptance, then back off to several seconds when processing takes longer. const delay = Math . min ( 8000 , 1000 * 2 ** slowChecks ); Add jitter when many guests finish at the same time. Stop when the state is terminal, the page is gone, or a server-provided retry time says to wait longer. SSE fits one-way progress Server-Sent Events are attractive when the server only pushes status. The browser reconnects with a last-event ID, and the wire format is simple. But mobile networks and some intermediaries silently kill idle connections. Send occasional heartbeats and treat reconnection as normal. The reconnect handler must fetch current state because events may have been missed beyond the server replay window. Do not keep one SSE stream per file. Subscribe by guest session or album and filter authorized upload IDs on the server. WebSockets add more responsibility WebSockets make sense when the client also sends frequent commands over the same channel or when a host moderation console needs many rapid updates. For a guest waiting on two files, they add connection authentication, heartbeat, reconnect, replay, and load-balancer complexity without much user benefit. Never rely on the so

The trust proxy setting is an important concept in backend development, especially when implementing rate-limiting in our APIs. But deciding its accurate value depends heavily on our deployment topology. When we deploy our application in production, the client may not talk directly to our backend. There may be 1 or more proxies in between who forward the request to the next proxy or the backend server. Those proxies can be Load balancers, API gateways, reverse proxy like nginx or any custom service. So effectively, our request has to do some 'hops' over these proxies to reach backend. When we implement rate limiting in app to prevent the DOS attack, we generally intend this rate limit on the basis of client IP address. And this works fine when client request reaches our backend directly. But when we have multi-hop architecture, the simple setup won't work as expected. Because the most recent IP will be of the proxy and not the client. So all the traffic coming from different users will be considered from the single client(our own proxy) and thus there will be false positives as the rate limiting will trigger much often. In this scenario, we must tell our backend to ignore these extra hops(i.e. to trust our proxies). This is done by specifying trust proxy. If there is 1 proxy between client-server we set trust proxy to 1; if there are 2, or more, we set it accordingly. This will ensure our express app skips(trusts) these IPs, and accurately figures out actual client IP. The originating IP address of client is identified from 'X-Forwarded-For' header by the express app. But setting trust proxy is not that straightforward. The numerical value for trust proxy will not work in every case. If there are different paths from which our request reaches backend, there is a chance that the number of proxies may be different in each path. For example - internal vs external traffic: External(public) traffic: (Client -> Web Application Firewall -> Load balancer -> Reverse Proxy ->

Signed upload sessions expire. Event contribution windows close. Storage reservations are reclaimed. These are normal lifecycle events, but many interfaces reduce all of them to “Upload failed.” A better protocol makes expiration explicit and recoverable where policy allows it. Distinguish three clocks An upload workflow usually has at least three deadlines: the event contribution window; the server-side upload intent expiry; the short-lived storage credential expiry. They should not share one timestamp. The event may accept contributions until midnight while a credential lasts five minutes and an intent can be renewed for an hour. Return the clocks in the session response with server time: { "serverNow" : "2026-07-17T18:00:00Z" , "eventClosesAt" : "2026-07-18T00:00:00Z" , "intentExpiresAt" : "2026-07-17T19:00:00Z" , "credentialExpiresAt" : "2026-07-17T18:05:00Z" } The client can display useful warnings without trusting its own clock for authorization. Model expiration by state A credential expiring during transfer is different from an intent expiring before completion. Use stable reasons: credential_expired -> request renewal intent_expired -> reconcile committed parts, then renew or restart event_closed -> stop new work, preserve local recovery guidance Do not automatically restart from byte zero. First ask the control plane which parts were committed and whether the original object key remains valid. Renew narrowly A renewal endpoint should accept the upload ID and prove continuity with the guest session. It rechecks event state, file policy, rate limits, and committed size. The response returns a new credential for the same object. Do not let the browser extend an intent indefinitely. Define a maximum session age and a bounded number of renewals. Long uploads may receive a larger initial policy based on file size and observed throughput. Handle the closing boundary fairly Decide what happens to an upload already transferring when the event window closes. Reasona

A PageSpeed Insights run flags a high Time to First Byte. The ticket lands on the theme backlog. Hosting gets upgraded. A CDN is added. The next lab run still shows a slow first byte on the same priority URL. In our experience the miss is often earlier in the path: DNS, TLS, HTTP version, connection reuse, edge routing, or cache policy. Theme and plugin work still matter, but they sit after the network and delivery stack has done its job. If first byte is already late, paint and interactivity inherit that delay. What follows walks that request in order for teams who need to reduce TTFB before another theme rewrite. We stay on the network and delivery layers. For WordPress cases where code on the stack beats a bigger hosting plan, see Why Your WordPress Site Is Slow (It Is Not Always Hosting) . For LCP levers once first byte is under control, see A Quick Way to Fix LCP: Four Changes That Cut Time to Paint . What TTFB includes when you measure first byte in lab tools Time to First Byte (TTFB) measures how long the browser waits from the start of the navigation request until the first byte of the response arrives. In PageSpeed Insights and Lighthouse, it appears as a diagnostic timing. In WebPageTest and similar waterfall tools, you can split the same wait into DNS, TCP connect, TLS, and waiting (server or edge processing). That split is what makes network work actionable for delivery teams. TTFB is not a Core Web Vital , but it feeds Largest Contentful Paint and overall load feel. A page that spends 800 ms waiting for first byte has already used a large share of a mobile LCP budget before the hero image or heading can paint. Field data from Chrome UX Report may show Time to First Byte as a supporting metric. Lab tools remain the fastest way to prove a DNS or CDN change after a release, because you control the URL, location, and cache state of the run. When you read TTFB in a report, ask which hop dominated. Resolver delay looks different from a cold TLS handshake. A c

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Client-side media preflight can improve an upload experience, but it can also crash the page before the network request begins. A twelve-megapixel JPEG may be only four megabytes on disk and tens of megabytes after decoding. Creating several full-size canvases at once is enough to exhaust memory on older phones. Preflight is policy, not editing Decide what the browser must prove before transfer. Useful checks include file count, compressed byte size, declared type, readable dimensions, and a conservative duration limit for video. Avoid mandatory re-encoding unless the product truly needs it. Every transformation adds CPU time, memory pressure, battery use, and another failure mode. Process one file at a time A file picker may return twenty items. Do not decode all of them to build previews. Maintain a queue with one active decode on constrained devices and at most two on stronger ones. for ( const file of files ) { const result = await inspect ( file ); renderResult ( result ); await yieldToMainThread (); } The UI can list filenames immediately while dimensions and thumbnails arrive progressively. Prefer metadata over full pixels Use createImageBitmap with resize hints when supported. It can decode away from the main rendering path and avoid a full-resolution canvas for a small preview. const bitmap = await createImageBitmap ( file , { resizeWidth : 640 , resizeQuality : ' medium ' }); Always close bitmaps after drawing. Revoke object URLs when the component unmounts. Small leaks become large when guests select and remove files repeatedly. Handle orientation and color carefully Modern browsers generally honor EXIF orientation when decoding, but behavior differs across APIs and older engines. Test portrait photographs from real iOS and Android devices. Do not strip metadata silently if the original is supposed to remain untouched; upload the source file and treat the preview as disposable UI. Color differences between the preview and exported original are usually les

This is Part 8 of 10 , a bonus practice article with 70 code-output challenges . Each challenge asks you to predict the result before revealing the answer and reasoning. Complete series This Dev.to series has five core handbook articles plus five focused practice extras. Open the series page to move through the complete reading order: Part 1: JavaScript — core handbook, questions 1–120 Part 2: React — core handbook, questions 121–220 Part 3: React Native — core handbook, questions 221–420 Part 4: Performance & Architecture — core handbook, questions 421–560 Part 5: Senior & System Design — core handbook, questions 561–719 Part 6: Output-Based JavaScript Practice — bonus practice article Part 7: Coding Interview Practice — bonus practice article Part 8: Code Output Challenges — bonus practice article Part 9: Current React Native Interview Questions — new high-frequency practice article Part 10: Project & Production Interviews — senior project ownership and real-production practice How to use this challenge set Read the code, state the exact output or error, then explain the language rule. Do not run the snippet until you have committed to an answer. For React Native interviews, connect the JavaScript behavior to rendering, state updates, list handling, or the JavaScript thread when relevant. Skills tested Hoisting, scope, closures, and this Arrays, conditions, references, object behavior, and loose versus strict equality Promises, timers, async / await , and microtasks Common JavaScript patterns used in React and React Native interviews Code output challenges Challenge 1. Block-scoped counter Predict the exact output before opening the answer. let total = 0 ; for ( let i = 0 ; i < 3 ; i ++ ) { total += i ; } console . log ( total ); Answer and explanation Expected output: 3 Why: The loop adds 0, 1, and 2. Challenge 2. var callback loop Predict the exact output before opening the answer. for ( var i = 0 ; i < 3 ; i ++ ) { setTimeout (() => { console . log ( i ); }, 0

I was tired of buzzword-heavy AI projects and marginally impactful demos. Surely we can do something more inspiring with these LLMs than build another chatbot? For me, the answer is physical AI: the moment all those breakthroughs finally reach into the real world, in robots that see, move, and figure things out for themselves. I think it is the most exciting frontier in tech right now. It is also genuinely hard to break into, because it is not one field. It is about five of them stacked on top of each other: electronics, mechanics, programming, data, and AI. Eight months ago I started my own robotics journey from scratch, and I was completely overwhelmed. How do you get from blinking an LED to a humanoid that does your dishes? There are thousands of scattered tutorials out there, with no sense of what comes first, or what any of it is building toward. So I decided to build the map. Stealing the best idea from my favorite games: If you have ever played a factory-building or strategy game like Satisfactory or Civ Six, you know the feeling. You start with almost nothing, and you unlock new tech one satisfying step at a time. Those games are proof that we will happily spend hours mastering an intimidatingly complex system, as long as it is laid out as a clear tree of unlocks. So why not point that same instinct at learning something real? That is exactly what a tech tree is: a structured, visual path where each node is a skill and each connection is a prerequisite. You start at Curiosity on the far left and work your way right, through electronics, mechanics, code, data, and AI, all the way toward autonomous robots and humanoids. The idea is simple: turn gaming time into learning time. What the tree actually is Every node on the tree is a skill to learn, and the star-shaped nodes are hands-on projects where theory finally meets a soldering iron. Nodes are color-coded by discipline, so you can see at a glance whether you are in electronics, mechanics, programming, data s

I'm building a journal app in Kotlin Multiplatform and for this purpose I have created a zoomable timeline interface. This is a side-project where I reuse the timeline interface to display 4 million events imported from Wikipedia / Wikidata, scored using PageRank. There is more information on the about page. If you're interested in the stack: I use Kotlin Multiplatform extensively, with Compose Multiplatform for the UI, communicates with the backend using Kotlinx-RPC and behind the hood a simple

Welcome to Day 5! Today we shift from volatile, temporary in-memory variables to persistent storage and application durability . You will learn how to interact safely with your operating system's file system, read/write structured industry data patterns, handle real-world operational crashes gracefully, and keep execution timelines documented using professional logging architectures. 💾 1. File Handling & pathlib 📄 Python's pathlib module treats file paths as smart object structures instead of plain text strings. This avoids bugs caused by differing slash directions across operating systems (Windows uses \ , while Mac/Linux use / ). Reading ( "r" ): Loads file contents into memory. Writing ( "w" ): Erases any existing file contents and writes a fresh payload from scratch. Appending ( "a" ): Targets the end of a file, adding fresh text without overwriting existing contents. 🌱 Easy Starter Example from pathlib import Path # Create a path reference pointing to a file in the current workspace directory file_path = Path ( " notes.txt " ) # Write text cleanly to a file space file_path . write_text ( " Hello from Day 5! " ) # Read data straight back into a string variable content = file_path . read_text () print ( content ) # Output: Hello from Day 5! 🏛️ Real-World Example: Multi-Platform System Telemetry Appender from pathlib import Path from datetime import datetime def log_system_status ( status_message : str ) -> None : # Resolve home folder pathways seamlessly across Windows, Mac, or Linux systems target_dir = Path . home () / " app_workspace " / " telemetry " # Create the directory chain automatically if it doesn't exist yet target_dir . mkdir ( parents = True , exist_ok = True ) log_file = target_dir / " runtime_events.log " timestamp = datetime . now (). isoformat () # Secure stream channel using Python's standard file-open context manager with open ( log_file , mode = " a " , encoding = " utf-8 " ) as file : file . write ( f " [ { timestamp } ] STATUS: { status_mes

Event uploads fail differently from normal office uploads. A wedding guest may move between venue Wi-Fi and mobile data, lock the phone while a video is transferring, or close the browser as soon as the progress bar reaches 100%. Hundreds of devices can share one access point, and users rarely wait around to diagnose an error. The usual POST request plus optimistic success toast is not enough. A reliable browser flow needs a small protocol that distinguishes local preparation, network transfer, server acceptance, media processing, and final availability. This article describes a platform-neutral design for that protocol. The five states users actually experience Model each file as a durable state machine: selected -> preparing -> transferring -> accepted -> processing -> ready Add terminal or recoverable branches: preparing -> rejected_local transferring -> paused | retryable_error | expired accepted -> processing_error processing -> ready | processing_error The key distinction is between transferring and accepted . The browser may have sent every byte while the server has not yet committed the upload. Showing “done” at that boundary creates the most frustrating failure: the guest deletes the original, but the organizer never receives it. Give every file a client-generated identity Create an upload ID before the first network request. A UUID is sufficient when combined with the event identifier: const uploadId = crypto . randomUUID (); const uploadIntent = { uploadId , eventId , name : file . name , size : file . size , type : file . type , lastModified : file . lastModified , }; Send that identity when creating the server-side upload session. If the browser retries after a timeout, the server returns the existing session instead of creating a duplicate. This is idempotency at the workflow level. A guest can tap “retry” without having to understand whether the first request reached the server. Separate the control plane from file bytes Use a small JSON API for sessi