Your monthly OpenAI or Anthropic invoice tells you how much you spent. It doesn't tell you which feature spent it, which model, or why last Tuesday cost three times as much as Monday. So at some point you (or your team) will build a metering layer: wrap the client, read usage off the response, multiply by a price table, ship it to a database. I did exactly that over the past few months while building an LLM observability service, and my numbers were wrong in five different ways before they were right. Every one of these failures was silent. No exception, no alert, just numbers that were quietly too low or too high. This is the list I wish someone had handed me. Pitfall 1: Streaming responses quietly report zero tokens OpenAI's Chat Completions API returns no usage data at all for streaming requests unless you pass stream_options: { include_usage: true } . No error, no warning. The stream just never contains token counts. If your metering reads usage off the chunks, every streaming call gets recorded as 0 tokens, $0. And since chat UIs are almost always streaming, that's most of your traffic. This one bit me twice in the same audit. First finding: all streaming calls in my own dashboard were $0. Second, nastier finding: I had a budget-gate feature that blocks calls once spend crosses a limit, and it waved every streaming call straight through — because as far as it could tell, streaming was free. The fix is to inject the option in your wrapper when the caller didn't set it: let injected = false ; if ( params . stream && params . stream_options ?. include_usage === undefined ) { params = { ... params , stream_options : { ... params . stream_options , include_usage : true }, }; injected = true ; } But there's a trap inside the fix. With include_usage on, OpenAI appends one extra chunk at the end of the stream that carries usage and has an empty choices array . Any downstream code that does chunk.choices[0].delta — which is most example code on the internet — will throw

Hackathons are intense. You've got a brilliant idea, a tight deadline, and often, limited sleep. The last thing you want is to spend half your precious time wrestling with database boilerplate, ORM setup, or SQL query syntax. This guide will walk you through building a functional Node.js backend for your hackathon project, focusing on speed and minimal friction, so you can spend more time on your core idea. The Hackathon Backend Challenge Typically, setting up a database and its interaction layer involves several steps: Schema Definition: Deciding on tables/collections, fields, types, and relationships. ORM/Driver Setup: Installing and configuring your database driver or ORM (e.g., Mongoose, Sequelize). Model Creation: Translating your schema into code, often with verbose syntax. Query Writing: Crafting SELECT , INSERT , UPDATE , DELETE statements or ORM methods for every data operation. Debugging: Fixing typos, schema mismatches, and complex join logic. This process, while fundamental, eats up valuable time that could be spent on features, UI, or even sleep. For a hackathon, you need to iterate rapidly, and database interactions should be the least of your worries. Strategy 1: Embrace Simplicity For many hackathon projects, you don't need highly optimized, production-grade queries from day one. You need functional queries that work quickly. Focus on getting data in and out reliably. Strategy 2: Natural Language for Data Modeling Instead of writing verbose schema definitions, think about how you'd describe your data to a non-technical person. For example, if you're building a task management app, you might say: "We need a collection of tasks. Each task has a title, a description, a due date, and a status (like 'pending' or 'completed'). Each task belongs to one user." This natural language description contains all the essential information for a data model, including relationships and field types. Strategy 3: Expressive Querying Similarly, when you need to fetch dat

Someone would ask a question in a public Slack channel. Every so often a couple of people would start to answer. Then the manager would step in, say what was going to happen, and the thread would go quiet. On its own, it looks like nothing. A decisive manager keeping things moving. But it was a team going quietly into debt, and the dead Slack thread was one of the interest payments. You already know tech debt. You cut a corner in the code to ship faster, and you pay interest on it later in bugs, slow changes, and the one file nobody wants to touch. Culture debt works the same way, except the corners you cut aren't in the code. They're in the norms, the expectations, and the relationships that decide how people actually work together. But tech debt is visible. You can see it, point at the file, write a ticket, argue about whether it's worth paying down. Culture debt is more dangerous because it gives you none of that. You don't watch it accruing. You see the symptoms, and by the time they show up, the debt has already compounded. Let me tell you how a team I joined got there. The reward was volume. The only thing that reliably got praised was pushing a lot of code. The manager was open about it...their whole framing of the job was being able to out ship anyone on the team. Everyone else stayed quiet. Nobody ever stood up and argued against quality. If you'd asked, the manager would have agreed that testing mattered and that quality mattered. Those things just never got prioritized. So over and over, what actually got rewarded (volume) quietly beat what everyone said they wanted. This didn't happen out loud. The reward silently won every time. You can guess what that bought. Planning went first, so features shipped in half finished states and got abandoned there. Testing basically didn't exist. We had a QA person, but things slipped through constantly. Bugs were everywhere. Plenty of features barely worked, and some just didn't. The human side hollowed out at the same

The problem with most web UIs is the gap between user action and visible feedback. A user clicks "like" and waits 200-400ms for the server to respond before the button changes. That delay reads as slowness even when the server is fast. The network round-trip is the ceiling. Optimistic UI inverts this: assume the operation will succeed, update the UI immediately, then reconcile with the server response when it arrives. If the server fails, roll back. React 19's useOptimistic hook gives you this pattern with minimal boilerplate and automatic rollback built in. The API const [ optimisticState , addOptimistic ] = useOptimistic ( state , // the current "real" state — synced from server updateFn , // (currentState, optimisticValue) => newOptimisticState ) optimisticState — during a pending transition, reflects the optimistic update. Once the transition completes, it reverts to state addOptimistic(value) — triggers an optimistic update, must be called inside startTransition Pattern 1: Like Button ' use client ' import { useOptimistic , useTransition } from ' react ' import { toggleLike } from ' @/actions/likes ' type LikeState = { liked : boolean ; count : number } export function LikeButton ({ postId , initialLiked , initialCount }: { postId : string initialLiked : boolean initialCount : number }) { const [ isPending , startTransition ] = useTransition () const [ optimisticState , addOptimistic ] = useOptimistic < LikeState > ( { liked : initialLiked , count : initialCount }, ( current ) => ({ liked : ! current . liked , count : current . liked ? current . count - 1 : current . count + 1 , }) ) function handleToggle () { startTransition ( async () => { addOptimistic ( ' toggle ' ) // updates UI immediately await toggleLike ({ postId }) // syncs with server }) } return ( < button onClick = { handleToggle } disabled = { isPending } > < Heart className = { cn ( ' h-4 w-4 ' , optimisticState . liked && ' fill-red-500 text-red-500 ' ) } /> < span > { optimisticState . count }

Introduction I've spent way too much time trying to come up with some generic introduction for this story, but then I realized none of you probably want to read that anyway. So instead, I'll just jump straight into the story—which is why you're here in the first place. The day I received the requirements The story begins when I received the requirements for a new feature that allows Teachers to share their presentation to review slides before the Lecture begins, so we would have teachers aids using the web version and seeing a screenshare from the main pc powerpoint, at first I thought maybe we can use HLS or RTMP for this and be okay with the 3 seconds delay that it has, but then I continued reading the ticket, we also needed the user to move to the next and previous slides via the web application, which immediately threw my initial idea out of the window. This is because if the user needs to interact with the application there is no way it will be usable without almost immediate feedback. Since we needed to show this to the client quickly we had 2 weeks to implement this feature, so before I did anything, I stopped and started drafting a simple design doc, which besides the fancy name was really just a document with my raw notes taken from research and comparisons between different solutions. After spending some time doing research and looking into different architectures and engineering blogs from companies like Twitch, Slack and Discord, I narrowed the possibilities down to four common architectures used for this type of use case. Architecture Options P2P Mesh This approach revolved around a user establishing WebRTC connections with every other user in the room. Besides being difficult to manage in terms of connections and sessions, it had one fatal flaw: network and CPU overhead. If we had twenty users in the room, every participant would maintain nineteen separate peer connections while sending nineteen streams, quickly consuming both CPU and bandwidth. MCU (M

submitted by /u/deepCelibateValue [link] [留言]

This week's Java roundup for July 6th, 2026, features news highlighting: the GA release of TornadoVM 5.0; point releases of JHipster, Keycloak and Google ADK; maintenance releases of GraalVM Native Build Tools and Micronaut; the OmniFish Build of Payara and introducing Vidocq, a new implementation of the Jakarta EE 11 Core Profile and MicroProfile 7.1. By Michael Redlich

Google and AIM launched ATL Saathi, a Gemini-powered AI tool empowering Indian educators in robotics labs.

Washington D.C. has become a battleground for Uber and Waymo's competing views.

This is a submission for Weekend Challenge: Passion Edition 📌 TL;DR I found this challenge on the...

Davide de Paolis discusses the realities of rolling out cloud infrastructure compliance without fracturing developer relations. Drawing from a real-world platform team reboot at Sevdesk, he explains how to implement "minimum viable governance" on AWS, utilize event-driven Slack alerting to automate policy feedback, and shift from rigid enforcement to high-empathy, data-driven collaboration. By Davide de Paolis

Hello, I'm Rijul. I'm building git-lrc, a micro AI code reviewer that runs on every commit. It's free...

This is today’s edition of The Download, our weekday newsletter that provides a daily dose of what’s going on in the world of technology. Sperm donors need limits, says a European fertility group Ties van der Meer doesn’t know how many siblings he has. The 47-year-old was conceived at a private fertility clinic using sperm…

Your AI agent for autonomous web app testing Discussion | Link

Oppo's Watch X3 is a Wear OS watch that'll outlast all of its rivals.

Workflow mapping for consultants running multiple clients Discussion | Link