今日已更新 328 条资讯 | 累计 20300 条内容
关于我们

标签:#beginners

找到 345 篇相关文章

AI 资讯

SQL Pattern Series #1: The Presence Pattern

Thinking in terms of existence instead of lists SQL Pattern Series #1 of 21 A collection of practical SQL patterns that help developers recognize common solutions to recurring database problems. What You'll Learn In this article you'll learn: When EXISTS and IN solve the same problem The difference between set membership and existence Why the underlying mental model matters When I typically reach for EXISTS Most SQL developers write a query like this at some point: SELECT c . CustomerID , c . CustomerName FROM Customers c WHERE c . CustomerID IN ( SELECT o . CustomerID FROM Orders o ); And it works. But sometimes it isn't the best way to think about the problem. The Question Behind the Query Many SQL problems can be framed in two different ways. Set Membership Is this value in a set? WHERE CustomerID IN (...) Existence Does at least one matching row exist? WHERE EXISTS (...) Both approaches often return the same result. But they represent different mental models. The Presence Pattern The Presence Pattern is useful when you do not actually care about the values being returned from a related table. You only care whether a matching row exists. For example: Customers who have placed an order Users who have logged in Employees assigned to a project Products that have sales In these cases, the question is often: Does a related row exist? rather than: What values are contained in this list? Example Using EXISTS SELECT c . CustomerID , c . CustomerName FROM Customers c WHERE EXISTS ( SELECT 1 FROM Orders o WHERE o . CustomerID = c . CustomerID ); The subquery is correlated to the outer query. Conceptually, SQL asks: For this customer, does at least one matching order exist? As soon as the answer becomes true, the condition is satisfied. Why This Pattern Matters Many SQL developers initially learn syntax. Over time, they discover that query writing is really about choosing the right mental model. The Presence Pattern encourages you to think in terms of: existence relationshi

2026-05-30 原文 →
AI 资讯

You'll not be replaced by AI if ...

There are many reasons why one may not be replaced by AI, not even by a possible future ASI. Here's one reason that may just apply to you! ❤️ You'll not be replaced by AI if you can generate creative ideas faster than AI can implement them! 🫡🚀 Note for critics: Current AI models (as of May, 2026) are not advanced enough to implement complex ideas without human interventions. But even if a possible future Artificial Super Intelligence (ASI) implementation can do so, laws of physics like massive energy requirements, environmental concerns etc. will prevent the implementation to replace the work of Billions of people world-wide. Our hardware advancement rate is far far slower compared to our software advancements. We humans are far more efficient and compatible to planet earth compared to the hardware we've invented. Fayaz Follow A Software Engineer who is not afraid of being replaced by AI, loves coding and writing with and without using AI, and values human life and human dignity far more than technological advancements.

2026-05-30 原文 →
AI 资讯

You're Using Git Wrong — How Worktrees Will Change Your Workflow Forever

You have a pull request open. Tests are failing. Your PM asks you to fix a production bug — right now. You have two choices: Stash your current work, switch branches, fix the bug, switch back, unstash Clone the entire repo again to a separate folder Both are terrible. But there's a third option most developers don't know about. What Are Git Worktrees? A worktree is a linked copy of your repository that lets you check out a different branch in a separate directory — without switching your current working tree. # While working on feature/login, create a worktree for a hotfix git worktree add ../project-hotfix fix/production-crash # Fix the bug in a SEPARATE directory cd ../project-hotfix # ... make changes, commit, push ... cd ../project # You're STILL on feature/login. Nothing stashed, nothing lost. No stashing. No cloning. No context switching overhead. Why This Is a Superpower 1. Parallel Branches Without the Pain # Review a PR without touching your current work git worktree add ../pr-review feature/new-dashboard cd ../pr-review git log --oneline -5 # Check the commits npm test # Run the tests cd ../project git worktree remove ../pr-review 2. Side-by-Side Comparison Want to compare your branch against main? Open them in two editor windows: git worktree add ../project-main main # Now open ../project/ (your branch) and ../project-main/ (main) side by side 3. CI Debugging Without Stopping Everything # Keep working on feature/x while debugging CI on a specific commit git worktree add ../ci-debug 7a3f9e1 cd ../ci-debug npm ci && npm test # ... debug CI failure without touching ../project/ 4. Documentation and README Updates The classic "quick fix while in the middle of something": git worktree add ../docs-update main cd ../docs-update # Edit README, commit, push cd ../project git worktree remove ../docs-update # Back to your feature branch, zero context loss The Workflow That Changed My Life Here's my daily workflow now: # Monday morning: start feature git checkout -b f

2026-05-30 原文 →
AI 资讯

I'm 15, Built My First Real Project in 4 Days, and Put It on Gumroad

I'm 15 and Built an AI Energy Dashboard with Next.js 15 + Groq Hey Dev.to! 👋 I'm a 15-year-old student developer from South Korea. I just finished my first real production project — FuelScope AI. What is it? An energy market intelligence dashboard that uses Groq's Llama 3.3 70B to summarize real energy news in real time. 🔗 Live Demo: https://fuelscope-ai.vercel.app What it does ⛽ Regional gas price cards 📈 Energy stock tickers (XOM, CVX, SHEL) 🤖 AI-summarized energy news (Llama 3.3 70B via Groq) 🗺️ Interactive Mapbox station map 📍 GPS nearest station finder 🎨 Apple-inspired clean design Tech Stack Next.js 15 + TypeScript Tailwind CSS Groq API (Llama 3.3 70B) — FREE tier GNews API — FREE tier Mapbox GL JS Vercel deployment What I learned This was my first time building something with: Real API integrations AI summarization pipeline Production deployment on Vercel Apple design system principles Honestly learned more in 4 days building this than months of tutorials. Honest disclosure Gas prices and stock data are mock values — the README includes guides for swapping in real APIs (EIA, Alpha Vantage, etc.). The AI news summaries are 100% live though. Template I'm selling the template for $19 on Gumroad if anyone wants to build on top of it: 👉 https://LZF01.gumroad.com/l/djzoaj Would love any feedback from the community! 🙏 Built with Next.js 15, Groq, GNews, Mapbox

2026-05-30 原文 →
AI 资讯

Learning Progress Pt.22

Daily Learning part twenty-two. I haven't been active in three days due to Eid Al‑Adha. On Tuesday I went to my family house, where we go once in a while. We call it the family house because that's where my grandmother, uncles, aunts, and cousins live. I didn't bring my laptop with me because I wanted to spend some time with my family, which I haven't done in months. I stayed there for the two days of Eid. Today I came back by bus. I was supposed to arrive at 17:00, but due to traffic I arrived at 18:40. When I arrived I ate a small sandwich and got back to work. I started the session at 19:30. The first thing I did was complete the HTML Tables section. It was difficult to learn (at least for me). It covered HTML Tables, Table Borders, Table Sizes, Table Headers, Padding & Spacing, Colspan & Rowspan, Table Styling, Table Colgroup, Exercises, and finally the Code Challenge. Then I did a quiz and the Unit 2 test in Khan Academy and also completed one lesson in Unit 3. Now I have started a Tic‑Tac‑Toe challenge in Python. I watched a video on the minimax algorithm, which the game uses. I have started coding, but I am far from finishing it. I am ending today's session at 23:40. Eid Al‑Adha Mubarak to all Muslims. "Speak good or remain silent." Prophet Muhammed (peace be upon him)

2026-05-30 原文 →
AI 资讯

I Built a Simple Web App to Discover the Meaning Behind Names 🚀

Hello Dev Community 👋 I recently built my first web project called Namastra — a simple tool to explore the meanings, origins, and insights behind names. 👉 Live Demo: 💡 Why I built this I noticed that many people are curious about: What their name means Where their name comes from What personality or cultural meaning it carries But most websites are: Too slow Full of ads Hard to navigate So I decided to build something simple, fast, and clean. ⚙️ What Namastra does With Namastra, users can: 🔍 Search any name instantly 📖 Get meaning and origin 🌍 Learn cultural background ⚡ Use a clean and fast interface 🛠️ Tech Stack I built this project using: HTML CSS JavaScript GitHub (version control) Netlify (deployment) Hosted here: [Netlify] Code managed via: [GitHub] 🚧 Challenges I faced As a beginner developer, I faced challenges like: Designing a clean UI Making search functionality smooth Deploying with GitHub + Netlify Structuring data properly But I learned a lot through building it step by step. 🎯 What I learned How to build and deploy a full project How important UI simplicity is How real users think differently than developers How deployment pipelines work (GitHub → Netlify) 🚀 Future improvements I plan to add: More name data Better UI design Categories (religion, origin, country) Possibly AI-based name insights 🙌 Feedback welcome This is my first real web project, so I’d really appreciate your feedback and suggestions. Try it here: 👉 Thanks for reading ❤️ Happy coding!

2026-05-30 原文 →
AI 资讯

Python Day Three – Lists, Indices, and Packing Your Virtual Backpack 🎒

Welcome back to Day 3, Python dynamic duo! 🚀 If you survived Day 2 , you now know how to create variables and throw strings, integers, floats, and booleans into their own little cardboard boxes. 📦 But what happens when you’re building a game and your character needs an inventory? Or you're making a shopping list app? Creating 50 different variables like item1, item2, item3 will make you want to throw your router out the window. 🪟💻 Today, we are leveling up our storage game. We are moving out of single cardboard boxes and packing a Virtual Backpack: Enter Lists! 🎒🎉 🎒 What is a List? In Python, a List is a data structure used to store a collection of items in one single variable. Think of it like a backpack where you can stuff multiple things inside, keep them in a specific order, and pull them out whenever you need them. Creating a list is simple. You use square brackets [] and separate your items with commas: # Packing our survival backpack 🗺️ backpack = [ " map " , " flashlight " , " water bottle " , " protein bar " ] print ( backpack ) # Prints: ['map', 'flashlight', 'water bottle', 'protein bar'] The coolest part? Python lists don’t care what you put inside. You can mix strings, integers, and booleans all in one single backpack (though usually, it makes the most sense to keep similar things together). 🤯 The First Rule of Coding Club: We Start Counting at Zero! Here is where programming turns your brain upside down. 🧠🙃 If I asked you what the first item in our backpack list is, you’d logically say "map". And you'd be right in human language. But in Python-speak, computer memory starts counting at 0. This is called Indexing. To pull a specific item out of your backpack, you write the name of the list followed by the item's position (index) inside square brackets: backpack = [ " map " , " flashlight " , " water bottle " , " protein bar " ] # Pulling out the items using their index 🔍 print ( backpack [ 0 ]) # Prints: map (The absolute first item!) print ( backpack [

2026-05-29 原文 →
AI 资讯

How to Build a Coffee Subscription on Shopify That Actually Retains Customers (A Practical Guide)

If you've ever built or set up a subscription experience on Shopify for a coffee brand, you've probably run into the same problem most merchants face: The signup flow works great. The first order goes out. And then subscribers start quietly disappearing before the third delivery. This isn't a coffee problem. It's a subscription infrastructure problem — and it's almost always caused by the same handful of missing pieces in the system underneath the storefront. In this guide I'll walk through the practical setup decisions that actually move the needle on retention for coffee subscription businesses on Shopify — from choosing the right model and pricing structure to the fulfillment calendar, dunning logic, and cancellation flow that most setups skip entirely. Why Coffee Works So Well as a Subscription Product Before getting into setup, it's worth understanding why coffee is genuinely one of the better products to build a subscription around — when the infrastructure supports it. Predictable consumption cycle. A 12-oz bag of whole beans lasts roughly two to three weeks for a single drinker. That natural rhythm makes it easy to design a billing and delivery schedule that matches actual usage patterns. Daily habit. Roughly two-thirds of American adults drink coffee every day. A subscription removes the friction of reordering, and that convenience compounds into real retention over time. Freshness as a retention argument. Coffee quality degrades noticeably after roasting. Subscribers who care about quality genuinely prefer a recurring shipment over buying retail — which means freshness becomes a built-in reason to stay subscribed that most product categories simply don't have. The global coffee subscription market reached $808.8 million in 2024 and is projected to surpass $2.2 billion by 2033. The infrastructure opportunity for developers and merchants building on Shopify is real and still early. Step 1 — Choose the Right Subscription Model Before You Build The model choic

2026-05-29 原文 →
产品设计

My First Cybersecurity Writeup – VAPT Experience

Overview This is my first real-world cybersecurity VAPT experience inside an enterprise insurance company environment. I worked across network infrastructure, web applications, internal devices, and physical security — and learned how professional security assessments are actually performed beyond labs and CTFs. Introduction I am a cybersecurity enthusiast focused on SOC operations, web application penetration testing, and vulnerability assessment. In this engagement, I worked on assessing the security posture of an insurance company across its network infrastructure, devices, web applications, and physical security controls. This was my first real-world experience working in an enterprise environment, and initially I was not fully confident about the workflow. However, with the guidance and support of my senior, I was able to understand the process step by step and actively contribute to the assessment. Objective Identify security vulnerabilities across network, web, and internal systems Assess exposure of critical assets Analyze potential attack paths in the environment Evaluate basic physical security controls Scope of Work Network infrastructure assessment Web application security testing Device-level security review Basic physical security evaluation Tools Used Nessus (vulnerability scanning) Burp Suite (web application testing & request interception) Nmap (network discovery & port scanning) GVM / OpenVAS (vulnerability assessment) OWASP ZAP (automated web scanning) Wireshark (packet analysis & traffic inspection) Approach / Methodology Performed network discovery using Nmap to identify active hosts and open ports Conducted vulnerability scanning using Nessus and GVM to detect known security issues Analyzed web application behavior using Burp Suite and OWASP ZAP Intercepted and inspected HTTP/HTTPS traffic to understand request/response flow Used Wireshark to analyze packet-level communication and detect anomalies Evaluated system exposure across internal devic

2026-05-29 原文 →
AI 资讯

Discovering Google Lighthouse . A Small Tool That Changed How I See Web Development

Today I discovered something I honestly should have explored a long time ago: Google Lighthouse. Funny enough, revamping my portfolio is one of those projects I kept pushing forward with the classic “I’ll do it tomorrow” mindset — and somehow tomorrow kept winning. But today I finally sat down and started improving it, and during that process, I came across Lighthouse. For anyone who hasn’t heard of it yet, Google Lighthouse is an open-source automated tool designed to help developers improve the quality of web pages. You can run it on almost any page — whether it’s public or behind authentication. What immediately caught my attention is that it audits things like: Performance Accessibility SEO Best Practices And probably a few more things I’m still discovering You can run Lighthouse directly inside Chrome DevTools, through the command line, or even as a Node.js module. The process is simple: You give Lighthouse a URL, it scans the page, runs a series of audits, and then generates a detailed report showing how your website performs. What makes it powerful is that it doesn’t just tell you what’s wrong it also explains: _ Why the issue matters How it affects users And how you can fix it _ As a beginner software engineer and developer, I’m slowly realizing that writing code is only one part of building great applications. Performance, accessibility, maintainability, and user experience matter just as much. And honestly, tools like Lighthouse make the learning process feel less overwhelming because they point you in the right direction. One thing I’ll say though don’t fall into the trap of chasing a perfect Lighthouse score instead of building useful projects. A lot of developers start optimizing numbers before validating whether the product itself solves a real problem. Lighthouse is a guide, not the final goal. For my portfolio specifically, Lighthouse exposed a few weaknesses immediately: Large unoptimized images Accessibility issues Slow-loading assets Missing metad

2026-05-29 原文 →
AI 资讯

I built an open-source tool that reverse-engineers any GitHub repo in 10 seconds

You know that feeling when you join a new project or want to contribute to an open-source repo, and you spend the first two days just trying to figure out where everything is? I did. Every single time. Clone the repo. Open the files. Stare at 47 folders. Wonder which one actually matters. Grep for the entry point. Follow imports down a rabbit hole. Give up and ask someone. That's not learning. That's just wasted time. So I built CodeAutopsy. What it does Paste any GitHub URL. That's it. CodeAutopsy clones the repo, parses every file into an AST (Abstract Syntax Tree), traces every import and dependency, and gives you: An interactive dependency graph showing exactly what imports what The entry points — where execution actually starts A blast radius map — click any file and instantly see everything that breaks if you change it An AI-generated architectural summary explaining what the codebase does, how it's structured, and how to get started Live Health Telemetry: An Edge API that generates a live SVG health badge (A to F grade). Drop the markdown in your README once. Every time you refactor and re-scan, your badge updates everywhere instantly. My own CodeAutopsy repo just hit 99/100. Drop the markdown snippet once and forget about it. What used to take days now takes about 10 seconds. The real problem it solves Every developer has been here: You're onboarding at a new job. The codebase has 200 files. Your tech lead says "just read the code." You spend a week feeling lost. You want to contribute to an open-source project. The repo has no architecture docs. You don't know where to start. You're doing a code review on a PR that touches 15 files. You have no idea what the blast radius of those changes is. CodeAutopsy solves all three. The interesting engineering problems The hardest part wasn't the AST parsing — it was keeping it serverless without hitting Vercel's 504 timeout limits, while making the AI analysis feel instant. The Serverless Timeout Hack: Doing AST extra

2026-05-29 原文 →
AI 资讯

Weekly Dev Log 2026-W07

🗓️ This Week Completed two more sections of the SwiftUI tutorial 🦾 As I continue working through the tutorial, I can feel my understanding of SwiftUI fundamentals becoming more solid 🔥 It was my first time posting a standalone article about reverse engineering📝 If you're interested, feel free to check it out 👇 A Curious Journey Into Reverse Engineering an AI-Generated Python .exe Umitomo Umitomo Umitomo Follow May 26 A Curious Journey Into Reverse Engineering an AI-Generated Python .exe # beginners # reversing # security # python 5 reactions Comments Add Comment 5 min read I started creating UI designs for my future portfolio website in Figma. I was able to roughly sketch out the overall structure of the site, but I also realized how difficult it is to create modern and stylish UI designs. (It really made me realize I don’t have much design sense yet 😂💦) While struggling with the design process, I came across several articles about Figma MCP . That made me interested in exploring how generative AI could help with UI design ideas, so I decided to start researching Figma MCP further. Completed Securing AI Systems room from the AI Security Learning Path on TryHackMe this week🤖 📱 iOS (SwiftUI) Worked through the SwiftUI tutorial and completed "Create an Algorithm for Badges" and "Add inclusive features" 🌐 Web Development Posted my weekly dev log on Dev.to and a standalone article about my first attempt at reverse engineering 📝 Created rough portfolio website UI layouts in Figma Used shadcn/ui component library design templates in Figma Started learning UI design in Figma using community resources 🔐 Security (TryHackMe) Completed Securing AI Systems room (part of the AI Security Learning Path) on TryHackMe. 💡 Key Takeaways 📱 SwiftUI Learning Add inclusive features Learned that SwiftUI automatically adapts UI elements for Light and Dark Mode by default. Learned how to preview and compare Light and Dark Mode layouts in the Xcode canvas. Understood that system-provided sema

2026-05-29 原文 →
AI 资讯

Git for GitHub: How to use simple Git commands to manage a GitHub repository

Recently, I was working on creating a website on a cloud-based IDE (CodeHS). One night, I was editing, and then when I was done, I simply turned off my monitor and disabled my mouse and keyboard. Then, the next day at school, I continued to work on the website, and made significant changes. When I got home, I made more significant changes, but then realized something very important. What I realized is that when I continued to work on the project at home, the cloud-based IDE hadn't refreshed to the new code, and overwrote the work I did at school when I saved my new work. So, what is the purpose of me telling you this? Is it to say that you should always close your code editor when you're done working, or some other trick to prevent this from happening? No, it definitely is not. After the initial panic, I realized that the cloud-based IDE had a history section, which has a detailed log of every change that happened to every file. I then looked back at my old copy, copied the changes, and put them back into my new code. Now, imagine you aren't using a cloud-based IDE, and your just editing a file on your computer, in an IDE, or simply your terminal. To clarify, Git is not cloud-based, it is local, (sitting on your computer), that connects to the cloud (GitHub). What happens when something breaks? For some environments, this could be catastrophic, and make you loose a lot of work. When you make an update to a file, the last state and all the states before it are gone. But, this isn't the only thing that can happen. When you use a version control system (VCS), like Git, you can always go back to your previous commits, (snapshots of your code). The work I almost lost wasn't very important; that work didn't effect anyone, except myself. Imagine what would happen if I was working on something more important, or even just working on something for a job. Before learning how to manage your project, it helps to understand what Git actually is. Git is overwhelmingly the most po

2026-05-29 原文 →
AI 资讯

I Just Wanted to Scrape One Page. Why Did I Write 50 Lines of Puppeteer?

Last Friday at 4:30 PM, my product manager walked over: "Hey, can you grab the titles from the Hacker News homepage and send me an Excel file?" I thought: That's it? Five minutes tops. Two hours later, I was still debugging CSS selectors. How Things Spiraled Out of Control Step 1: Initialize the Project mkdir hacker-news-scraper && cd hacker-news-scraper npm init -y npm install puppeteer Hit enter, waited three minutes. Puppeteer needs to download a full Chromium browser — over 200 MB. I stared at the progress bar and started questioning my life choices. Step 2: Write the Code "It's just a document.querySelectorAll , right?" That's what I thought. Then I opened my editor: const puppeteer = require ( ' puppeteer ' ); ( async () => { const browser = await puppeteer . launch ({ headless : true , args : [ ' --no-sandbox ' , ' --disable-setuid-sandbox ' ] }); const page = await browser . newPage (); try { await page . goto ( ' https://news.ycombinator.com ' , { waitUntil : ' networkidle2 ' , timeout : 30000 }); await page . waitForSelector ( ' .titleline > a ' , { timeout : 10000 }); const titles = await page . evaluate (() => { const items = document . querySelectorAll ( ' .titleline > a ' ); return Array . from ( items ). map ( el => ({ title : el . textContent , url : el . href })); }); console . log ( JSON . stringify ( titles , null , 2 )); } catch ( err ) { console . error ( ' Scraping failed: ' , err . message ); } finally { await browser . close (); } })(); I counted: 27 lines. And this is the minimal version — no User-Agent spoofing, no retry logic, no proxy support, no concurrency control. Add all of that and you're well past 50 lines. Step 3: Run It node index.js Error: Navigation timeout of 30000 ms exceeded . Switched to domcontentloaded , got past that. But then waitForSelector timed out — because .titleline was a relatively new class name. Hacker News had silently changed it from .storylink at some point, and nobody sent me the memo. Step 4: Debug Set head

2026-05-28 原文 →
AI 资讯

Building Metadata Capabilities in Apache SeaTunnel: A Committer’s Journey

Recently, Apache SeaTunnel welcomed several talented and highly motivated new Committers, and Wang Xuepeng is one of them. As a long-time contributor, Wang Xuepeng’s promotion to Committer was no coincidence. Over the years, he has quietly contributed a tremendous amount to the community, and everyone has witnessed his dedication. From first stepping into the open-source world to becoming a Committer of an Apache top-level project, he has accumulated plenty of stories and valuable insights along the way. What inspired his journey? What experiences and lessons does he want to share with the community? Let’s take a closer look at this exclusive interview with him! Personal Introduction Interview Transcript How long have you been involved in open source? What attracts you to open source? I started getting involved in open source in 2023. What attracts me most is the sense of achievement when the code I write can actually be used within the industry. When did you start contributing to SeaTunnel? What was the trigger? I joined WhaleOps in 2023, which was also when I first started engaging with open source. Now that you’ve been elected as a SeaTunnel Committer, could you summarize your contributions to the community, including both code and non-code contributions? Most of my major feature PRs have focused on building SeaTunnel’s metadata capabilities. When running SeaTunnel jobs and writing job configurations, users often need to manually enter datasource connection information. For file-based tasks, users also need to manually define field mappings. To address these issues, I designed an SPI interface called MetadataProvider . The interface mainly exposes two methods: Map<String, Object> datasourceMap(String connectorIdentifier, String metaDataDatasourceId); Optional<TableSchema> tableSchema(String metaDataTableId); Previously, some users in the community mentioned that datasource usernames and passwords were stored in Nacos with read-only access permissions. In scenario

2026-05-28 原文 →
AI 资讯

Understanding known_hosts and Host Key Verification: What It Protects Against and How TOFU Works

That "authenticity of host can't be established" message isn't just noise. Here's what's actually happening — and why blindly typing "yes" is a security mistake. Every developer has seen this: The authenticity of host 'example.com (203.0.113.1)' can't be established. ED25519 key fingerprint is SHA256:abc123xyz... Are you sure you want to continue connecting (yes/no/[fingerprint])? Almost everyone types yes without reading it. Then they move on. This message is SSH trying to protect you from one of the most dangerous attacks in network security: the man-in-the-middle attack. Understanding what's happening here — and what the ~/.ssh/known_hosts file actually does — will change how you think about every SSH connection you make. The Problem SSH Is Solving When you connect to ssh user@example.com , how do you know you're actually talking to example.com ? You can't rely on the IP address — IP addresses can be spoofed or rerouted. You can't rely on DNS — DNS can be poisoned. You can't rely on the network path — traffic can be intercepted at any point between you and the server. Without verification, an attacker positioned between you and the server could intercept the connection, pose as the server, decrypt everything you send, re-encrypt it, and forward it along. You'd type your password or authenticate with your key and never know the attacker saw every keystroke. This is a man-in-the-middle (MITM) attack . It's not theoretical. It happens on compromised networks, corporate proxies, malicious Wi-Fi hotspots, and misconfigured infrastructure. SSH's defense is host key verification . Every SSH server has a unique cryptographic identity — its host key. Before you exchange any sensitive data, the server proves it holds the private key corresponding to a public key you've previously verified. If the keys don't match, SSH warns you — loudly. What a Host Key Actually Is When OpenSSH is installed on a server, it automatically generates a set of host key pairs. These live in /etc

2026-05-28 原文 →
AI 资讯

A-Z AI Glossary

AI Glossary: A to Z An A-to-Z glossary of AI terms, created with help from AI itself. Because in 2026, the best way to study AI is apparently to ask AI itself. 🤣 Written for beginners and practitioners alike. Each term includes a plain English definition and a real-world example. Quick Navigation A · B · C · D · E · F · G · H · I · J · K · L · M · N · O · P · Q · R · S · T · U · V · W · X · Y · Z ↑ Back to top A Term Definition Example Agent (AI Agent) An AI system that perceives its environment, makes decisions, and takes autonomous actions to achieve a goal A coding agent that writes, runs, and debugs its own code without human intervention AGI (Artificial General Intelligence) A hypothetical AI that can match or exceed human-level intelligence across any task — does not yet exist Often cited as a long-term goal by companies like OpenAI and DeepMind AI (Artificial Intelligence) The field of computer science focused on building machines that can perform tasks normally requiring human intelligence ChatGPT writing an essay, an algorithm detecting cancer in X-rays AI Ethics The principles and practices for developing and deploying AI in ways that are fair, transparent, and safe Auditing a hiring algorithm to ensure it doesn't discriminate by gender or race AI Safety The field dedicated to ensuring AI systems remain reliable, controllable, and beneficial as they grow more capable Research into preventing AI from pursuing goals that harm people Alignment The challenge of ensuring an AI system's goals and behaviour match what its designers and users actually intend Preventing a powerful AI from optimising for a metric in a way that causes unintended harm Annotation The process of labelling raw data so it can be used to train supervised learning models Humans drawing bounding boxes around cars in images to train a self-driving model API (Application Programming Interface) A defined interface that lets software systems communicate with each other Calling the OpenAI API to

2026-05-28 原文 →
AI 资讯

No-Code Strategy Builder: Turning a Trading Idea Into Testable Rules

Most trading ideas start as vague thoughts. "Buy when RSI is oversold and price bounces from support." It sounds reasonable. But the moment you try to test or automate it, the ambiguity becomes obvious. What exactly counts as oversold? How is support defined? What qualifies as a bounce? When do you exit? Without precise answers, the idea cannot be tested, measured, or executed consistently. This gap between intuition and execution is exactly what no-code strategy builders are designed to close. Why vague trading ideas fail Most traders think in concepts rather than rules. "Buy the dip." "Trade strong momentum." "Enter when the trend looks healthy." These ideas feel intuitive, but they are unusable in practice unless translated into explicit logic. Without clear definitions, you cannot backtest a strategy, cannot repeat decisions consistently, and cannot diagnose why results change over time. Ambiguity leads to second-guessing. Second-guessing leads to inconsistent execution. Inconsistent execution makes performance impossible to evaluate. What a no-code strategy builder actually does A no-code strategy builder is a visual system that forces clarity. Instead of writing code, you select indicators, define conditions, combine logic using AND/OR rules, specify entries and exits, and then test the strategy on historical data. Conceptually, it works like assembling building blocks. Each block represents a condition such as "RSI below 30" or "price above moving average." When combined, those blocks form a complete, testable trading system. The key benefit is precision. From idea to testable strategy The transformation follows a predictable workflow. You begin with a loose idea, such as buying when a stock is oversold and starting to recover. You then break that idea into components. What defines oversold? What signals recovery? How do you enter? How do you exit? How much do you risk? Once those questions are answered, the idea becomes a set of explicit rules. For example,

2026-05-28 原文 →