Most developers have experimented with ChatGPT or GitHub Copilot. But when it comes to building AI-powered applications, simply calling an LLM API isn't enough. Understanding what's happening behind the scenes helps you design systems that are scalable, reliable, and cost-effective. In this article, we'll explore four concepts every software engineer should know: tokens, embeddings, transformers, and Retrieval-Augmented Generation (RAG). 1. LLMs Think in Tokens, Not Words One of the biggest misconceptions about Large Language Models (LLMs) is that they understand words like humans do. In reality, they process tokens, which are smaller units of text. For example: Prompt: Explain dependency injection in Spring Boot. is first converted into a sequence of tokens before the model processes it. Why does this matter? API pricing is based on the number of input and output tokens. Longer prompts increase latency and cost. Every model has a maximum context window measured in tokens. When building AI applications, prompt design isn't just about getting better answers—it's also about optimizing performance and cost. 2. Transformers: The Breakthrough Behind Modern AI Before 2017, language models processed text one word at a time using architectures like RNNs and LSTMs. They struggled with long conversations because earlier context was gradually forgotten. The introduction of the Transformer architecture changed this with a mechanism called self-attention. Instead of reading text sequentially, transformers analyze the relationships between all tokens in a sentence simultaneously. Consider this sentence: "The server restarted because it ran out of memory." The model understands that "it" refers to "the server", not "memory", by assigning attention to the relevant words. This ability to capture context efficiently is what powers modern LLMs like GPT, Gemini, Claude, and Llama. 3. Embeddings Enable Semantic Search Suppose a customer searches: "How can I get my money back?" But your

The maps and images show the extent of destruction and give rescue operations a tool to find any remaining survivors.

A device that resets in the field is not always the hardest problem. The harder problem is a device that resets, comes back online, and leaves no evidence about what happened before the reboot. That is where a firmware black box becomes useful. This is the DEV.to edition of a Silicon LogiX technical article. The canonical English source is linked at the end. What a firmware black box is A firmware black box is a small diagnostic subsystem inside the firmware. Its job is to preserve enough information to support post-mortem analysis after a reset, watchdog event, HardFault, panic or unexpected reboot. It does not need to record everything. It needs to record the data that helps answer the first diagnostic questions: why did the device reset? how long had it been running? which firmware build was installed? what state was the application in? which task was active? did the watchdog fire? did memory, stack or heap margins collapse? did the network, modem, BLE, Wi-Fi or OTA flow fail just before the reboot? Without that data, every field reset deletes most of the evidence. Why sporadic resets are expensive Rare embedded bugs are often more expensive than obvious failures. A crash that happens every time in the same function can usually be analyzed with a debugger, logs and a repeatable test. A reset that appears once every ten days on a customer device is different. The cause may depend on a combination of: temperature unstable power brown-out cable length enclosure heating network drops modem state memory fragmentation stack exhaustion long uptime race conditions a peripheral that stops responding an OTA edge case In the lab, the product may look clean. In the field, the environment changes. The customer report often becomes: "it rebooted", "it stopped communicating", or "we had to power-cycle it". That is not enough for firmware diagnosis. What to capture A good first version does not need to be large. Start with a compact structure that survives the next boot: reset r

React useIntersectionObserver Hook: Lazy Load & Detect Visibility (2026) You want to load an image only when it scrolls near the viewport. Or fire an analytics event the first time a card is actually seen . Or trigger "load more" when the user reaches the bottom of a list. Every one of these is the same question — is this element on screen yet? — and for years the answer was a scroll listener that fired hundreds of times a second, re-read getBoundingClientRect() on each tick, and still managed to miss the edge cases. IntersectionObserver is the browser API that answers that question correctly, asynchronously, and off the main thread. useIntersectionObserver is the hook that wires it into React without the useEffect / useRef /cleanup boilerplate — and without the leak-on-unmount and stale-closure bugs the hand-rolled version always ships. This post covers the real @reactuses/core API, the three patterns you'll actually reach for, and how to tune threshold , rootMargin , and root . SSR-safe and typed. Why Not Just Use a Scroll Listener? The old way to know whether an element was visible looked like this: listen to scroll , and on every event measure the element against the viewport. useEffect (() => { function onScroll () { const rect = el . getBoundingClientRect (); if ( rect . top < window . innerHeight ) { setVisible ( true ); } } window . addEventListener ( ' scroll ' , onScroll ); return () => window . removeEventListener ( ' scroll ' , onScroll ); }, []); This has two problems baked in. First, scroll fires on the main thread, dozens of times per second, and getBoundingClientRect() forces a synchronous layout each time — that's exactly the recipe for janky scrolling. Second, it only catches elements crossing the viewport ; the moment your scroll happens inside a container, you're re-deriving geometry by hand. IntersectionObserver flips the model. You hand the browser a target and a threshold, and it tells you — asynchronously, batched, off the scroll path — when

AWS launched Lambda MicroVMs, a new serverless compute primitive that runs each user session or AI agent in its own Firecracker virtual machine with hardware-level isolation, snapshot-based rapid launch, and state preservation for up to eight hours. Reddit community analysis found the minimum setup costs $3.03/day, roughly 9x Fargate spot pricing. By Steef-Jan Wiggers

New OpenAI Signals data shows how ChatGPT adoption is growing globally, with users increasing usage, exploring more capabilities, and driving growth across regions and languages.

Event-driven architecture promises scalability, but in Java-based real-time systems the tradeoffs only surface in production. Drawing on a Java/Kafka contact center platform handling 80k BHCC across 10k agents, this article details where the design breaks down—state management, partition limits, deduplication, JVM tuning, cascading consumer failures—and the Redis-backed patterns that fixed each. By Sagar Deepak Joshi

OKX is bringing together payments, identity and reputation into a marketplace for AI agents.

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