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The first time I audited seriously, I opened the biggest contract in the repo and started reading line one. Two hours later I had a headache and zero findings. I had memorized how the code worked without ever asking what it was supposed to guarantee. That is backwards, and it took me a while to unlearn it. Now I do not read Solidity first. I read the scope, and before I look at a single function body I write down what must always be true. Bugs are violations of those truths. If you do not know the truths, you are just admiring the code. Step one: write the invariants before you read An invariant is a property the protocol claims will always hold, no matter who calls what in what order. For a contest, I start with money and control, because that is where severity lives. Two questions cover most of it: Who can move funds, and under what conditions? What must always hold about the accounting? For a lending-pool-shaped protocol my starting invariant list looks like this, written in plain language before I care how any of it is implemented: The sum of all user deposits minus all borrows equals the pool's available liquidity plus outstanding debt. Accounting must reconcile. A user can only withdraw up to their own balance, never more, never someone else's. A position can only be liquidated when it is actually under the health threshold. Interest accrues monotonically, it never goes backwards in a way that lets someone repay less than they owe. Only the borrower, or a liquidator on an unhealthy position, can reduce a debt. Nobody except governance can change interest rate parameters or the oracle. Notice none of that mentions a function name. These are the promises. Now my job for the rest of the contest is simple to state: find an ordering of calls that breaks one of these. Step two: map the external entry points Funds do not teleport. Something has to be called from outside for state to change. So I list every externally reachable function, because the attack surface is

Originally published on nejckorasa.github.io . When a team moves from a monolith into microservices and event-driven, asynchronous systems, it inherits a class of problems that used to be someone else's: work that fails halfway through, steps that must not run twice, calls that return before the work is done. Temporal is a durable execution engine that handles a lot of this - you define a multi-step process, and it guarantees the process runs to completion even when workers crash in the middle. I've spent the better part of a decade building distributed systems in the money-movement core of banks - ledgers, payments, credit cards - a lot of it on Temporal, from short request-triggered workflows to ones that stayed open for weeks. This is the high-level guide I'd give a team making that jump: the principles worth internalising before you ship, not a full tutorial. Most of them aren't really about Temporal. They're the habits the async shift demands - Temporal just punishes you quickly when you skip one. Durable Execution: The Problem It Solves Distributed work fails in the middle. You call service A, it succeeds. You call B, it times out. The pod dies before C. Now you have half-finished work and no memory of how far you got. The usual fix is a pile of status columns, a cron job to find stuck rows, and retry logic hand-rolled for every step. Temporal's promise is that any process you start runs to the end. The runtime picture: there's a Temporal service (its own cluster), and your app runs worker processes that poll it and execute your code. As a workflow runs, Temporal records every step to an event history . If a worker dies, another picks the workflow up and replays that history to rebuild state, then carries on from where it left off, retrying anything that failed. The history is the source of truth, and it survives the crash. Most of the rules below fall out of that one fact. The Golden Rule: Workflows Decide, Activities Do There are two kinds of code in Tempora

This is Part 18 of my series on the Microsoft Agent Framework. You can read the original post over on lukaswalter.dev . In the previous article , we looked at observability for agents. The main idea was to make a run visible as a chain of model calls, tool calls, approvals, and workflow events. Testing starts from the same idea. An agent run is not one answer string. It is a small application flow with several boundaries: user input -> prompt and context -> model request -> model response -> tool selection -> tool arguments -> tool execution -> structured result or final answer -> routing or workflow state If the only test is an end-to-end prompt against a live model, all of those boundaries are mixed together. When the test fails, you do not know whether the problem is the prompt, the model, the tool schema, the router, the workflow, or the real dependency behind the tool. The solution is not to pretend that an LLM is deterministic. The solution is to test each boundary at the level where it is deterministic, then add a smaller number of evaluation-style tests for behavior that genuinely depends on the model. This post covers: fake model clients tool contract tests structured output tests routing tests workflow tests eval-style regression checks The examples use xUnit-style assertions, but the testing approach does not depend on xUnit. The snippets focus on the relevant testing boundary and omit some application-specific factory and workflow setup. Do not start with the live model A live model test is useful. It is also expensive, slow, sometimes flaky, and difficult to diagnose. That makes it a poor replacement for normal unit and integration tests. I use a testing pyramid for agent applications: evals realistic model and user examples application integration tests agent + tools + storage + workflow boundaries deterministic component tests fake model client, tools, schemas, routing The bottom layer should be the largest. It should catch ordinary programming mistak

A few weeks ago, I set out to build a small portfolio project: a Streamlit app that could take any tabular dataset, understand something about its structure, and give honest guidance on how to model it. I called it ContextLens . I expected it to be a practical exercise in Python, machine learning, and deployment. What I didn't expect was how closely it would connect with the same questions I work with every day in my PhD research on context-aware intelligent systems. The problem I started with Most introductory machine-learning tutorials follow a familiar sequence: Load a CSV. Choose a model. Train it. Check the accuracy. What often gets skipped is the layer of judgment that should come before any of that: Is this actually a classification problem or a regression problem? Is the target so imbalanced that accuracy becomes misleading? Is that "ID" column secretly leaking the answer into your model? Are there duplicate rows, missing values, high-cardinality categories, or too many features for the number of available observations? Experienced practitioners make these judgments almost automatically. But that reasoning usually remains invisible—it sits in someone's head rather than inside the system, where another person can inspect it. ContextLens is my attempt to make that layer visible. Upload a dataset, and it profiles the data, flags structural risks—missingness, duplicate rows, likely identifier columns, class imbalance, and high-dimensional settings—and adapts its evaluation guidance to what it finds before training a single model. The point is not simply to train a model. The point is to ask whether the modelling process makes sense in the first place. Why I call it "context-aware" rather than "AI-powered" I was deliberate about this distinction, just as I have been throughout my PhD work, and it turned out to be the most important design decision in the whole project. ContextLens does not claim to be intelligent in the way a human expert is. It does not hide its

"These are things that tend to be really hard."

Tesla's electronic door handles that have been linked to several deaths could lead to tougher safety rules for the entire auto industry. In a notice published today, the National Highway Traffic Safety Administration said that complaints about Tesla's mechanical door release don't warrant a defect investigation. Instead, the issue is better addressed through a broader […]

Following its Unpacked launch event for the Galaxy Z Fold 8 series, Samsung briefly opened a theme pub in the middle of London.

Seller is a dedicated Marketplace app for people who list and sell items frequently.

I wanted to add a background-removal tool to my site's image cluster that stayed true to the 100% client-side processing principle I already use for PDFs and image conversions. The path there was anything but linear: a library dropped over a licensing problem, a carefully chosen model that turned out more limited than expected, and a bug that froze the entire page — not just the tool — during computation. Here's the full build, including the parts that didn't work the first time. The starting problem: what's actually feasible for free? The initial idea was broad: remove backgrounds, and maybe unwanted objects too. The two tasks have very different difficulty levels. Removing objects requires inpainting — plausibly reconstructing the erased area — which in practice still means heavy generative models, impractical to run client-side with good quality on an average device. Removing a background , on the other hand, is a segmentation problem: separating a subject from its surroundings. That has much lighter models available, runnable entirely via WebAssembly with no server involved at all. So: background removal only, object removal shelved for later. The AGPL trap The first library that looked like a perfect fit turned out to be distributed under AGPL , a strong copyleft license. Free to use — but with a real catch for anyone embedding it in a public, closed-source web service: AGPL can require releasing the full source of the project that embeds it, under the same license. "Free for the end user" and "safe to drop into a closed-source commercial product" are two different questions, and it's worth answering the second one before writing integration code, not after deploying it. Before wiring any "free" AI library into a commercial project, check the exact license, not just the price tag. AGPL, GPL, and other strong copyleft licenses are fine for personal or internal tools, risky for a public closed-source product. The fix: switch to Transformers.js — Hugging Face's li

A nova fase dos agentes de IA: menos chat, mais operação. A OpenAI apresentou o Presence, uma plataforma para empresas implantarem agentes de voz e chat em atendimento ao cliente e fluxos internos. Para quem desenvolve sistemas, o ponto não é apenas colocar mais um chatbot em produção. A mudança relevante é tratar a IA como uma camada operacional: ela precisa participar de processos reais, com objetivos claros e resultados verificáveis. Um agente confiável precisa de mais do que boas respostas. Precisa receber o contexto certo, operar dentro de permissões bem definidas, deixar rastros auditáveis e saber quando transferir o caso para uma pessoa. Isso altera a decisão técnica. Escolher um modelo continua importante, mas arquitetura, integrações, observabilidade, avaliação contínua e governança passam a fazer parte do mesmo problema. A pergunta mais útil deixa de ser “onde podemos colocar IA?” e passa a ser: qual processo já está pronto para ser redesenhado com um agente de confiança? Fonte oficial: https://openai.com/index/introducing-openai-presence

Introduction Polymarket , and on-chain prediction markets like it, kept bothering me for one reason. Polymarket |世界最大の予測市場™ Polymarketは世界最大の予測市場であり、さまざまなトピックにわたって将来のイベントを取引することで、最新情報を入手し、知識から利益を得ることができます。 polymarket.com Who bet on what is visible in near real time. The moment a whale places a big bet on one outcome, everyone watching piles in behind them, and the odds move accordingly. That's not manipulation — it's just what happens with a public ledger. But it doesn't satisfy the simple wish to not reveal your prediction before everyone else does. So: could you build a prediction market that keeps your pick hidden until voting closes? To find out, I built Hidden League Forecast on Midnight , a privacy-focused blockchain. It's an MVP where you just guess the winner of a fictional soccer league (the World Cup just ended, so soccer was on my mind). Note What's a prediction market? A mechanism that expresses predictions about future events as prices. Think "which team will win the World Cup match," for example. If you want to learn more about prediction markets, this resource (Japanese) is a great start: https://zenn.dev/barabara/books/prediction-markets-structure The backend is written in Compact , Midnight's smart contract language. Note It combines the commit-reveal pattern with zero-knowledge proofs so that "the content of your prediction stays hidden, while only the aggregate stake becomes public." In this article, I'll walk through the contract code, showing what stays hidden and what becomes public at each step. Note This app runs on testnet. Demo Video After connecting Lace Wallet, you see your Shielded Address and balance. From here you can deploy a new market or enter an existing contract address to join one. The Overall Flow What's actually happening is simple. OPEN → REVEAL → AWAITING RESULT → RESOLVED → CLAIM Connect Lace Wallet, then deploy a market or join an existing one Pick one of 4 teams (Amber Foxes / Cedar Owls / Harbor Whales / Meadow Bears) and

These are the AC units we’ve trusted to cool our homes for months, if not years.

US robotics researchers flew to Venezuela with snakebots after getting a call.

The TK705STi’s highly responsive, low-latency performance makes gameplay ultra-realistic. For movies and TV? It’s a purely average home projector.

Airbus selected Scaleway as its sovereign cloud provider after a tender that scored protection against non-European extraterritorial legislation alongside technical capability. Airbus frames it as complementing multi-cloud, not exiting AWS. Practitioners note the pattern is spreading past hyperscalers to small US SaaS vendors, and that sovereignty claims still require verifiable controls. By Steef-Jan Wiggers

From musical instruments and games to play pieces that encourage balance and dexterity, these toys will engage your child’s mind and body.

“I think it should stand for artificial idiot,” one 9-year-old says. Here’s why kids of all ages are calling AI “disgusting” and “creepy.”

As part of my learning journey with Django, I wanted to build a project that would challenge me beyond the basics. I decided to create RecipeHub, a web application where users can create, manage, and share recipes while exploring recipes from other users. The project started from a Django starter template, but I customized it by adding new features, redesigning the interface, and deploying it online. Features RecipeHub allows users to: Register and log in Create, edit, and delete recipes Browse recipes by category Save favourite recipes Upload recipe images Access a personal dashboard Use the application in both light and dark mode The application is fully responsive, making it easy to use on both desktop and mobile devices. Technologies Used I built the project using: Python Django Django Allauth PostgreSQL Tailwind CSS DaisyUI HTMX Vite Gunicorn Render GitHub was used for version control throughout the project. Challenges One of the biggest challenges was deployment. While everything worked locally, deploying to Render required configuring PostgreSQL, environment variables, and static files correctly. I also encountered an issue with uploaded recipe images. Since the application is hosted on Render's free tier, uploaded media is stored on an ephemeral filesystem, meaning uploaded images are lost after redeployment. Learning why this happens gave me a better understanding of the difference between development and production environments. Another challenge was redesigning the dashboards. I wanted them to feel clean and modern instead of looking like a default Django application, so I spent time improving the layout, spacing, and responsiveness. What I Learned This project helped me improve my understanding of: Django project structure Authentication and user management CRUD operations Database relationships Responsive UI design Git and GitHub workflows Deploying Django applications Debugging real-world issues More importantly, it taught me how to troubleshoot proble

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The article discusses an experiment where a code assistant had to design an agentic system using LangChain4j documentation. The assistant created a coding framework capable of writing, testing, and debugging code autonomously. Results showed that two architectural patterns—supervisor and workflow—offered different trade-offs between flexibility and execution speed during debugging tasks. By Kevin Dubois, Mario Fusco