The core technologies used at ATRI are: 1. HTML: Foundation of web applications. Key elements include we use are: 1.1 Semantic HTML: Improves accessibility and SEO. 1.2 HTML5 APIs: Supports multimedia, graphics (Canvas, WebGL), geolocation, and local storage. 2. CSS: Enhances the visual appeal and user experience of web applications. Key aspects include: 2.1 CSS Preprocessors: SASS, LESS 2.2 CSS Frameworks: Bootstrap, Tailwind CSS, Bulma 2.3 CSS-in-JS: Styled-components, Emotion 2.4 Responsive Design: Media queries, Flexbox, Grid layout 3. JavaScript: Enables dynamic interactions on web pages. Core JavaScript technologies include: 3.1 ES6+ Features: Arrow functions, async/await, destructuring, modules 3.2 DOM Manipulation: Native APIs, jQuery 3.3 Event Handling: Bubbling, capturing, delegation

ATRI's deployment technologies includes 1 . React.js: It is a declarative, component-based JavaScript library. Key features: 1.1. Virtual DOM: Enhances performance by reducing direct DOM manipulation. 1.2. Component-Based Architecture: Reusable UI elements. 1.3. State Management: Context API, Redux, Zustand, Recoil. 1.4. Server-Side Rendering (SSR): Next.js for improved SEO and performance. 2 Angular A TypeScript-based framework. Key features: 2.1 Two-Way Data Binding: Synchronizes model and view. 2.2 Dependency Injection: Enhances modularity and reusability. 2.3 Angular CLI: Simplifies project setup and management. 2.4 RxJS: Enables reactive programming with Observables. 3. Vue.js: A progressive framework that combines the best of React and Angular. Features include: 3.1 Virtual DOM and Reactivity System: Enhances performance. 3.2 Single File Components (SFCs): Encapsulates HTML, CSS, and JavaScript. 3.3 Vuex for State Management: Centralized state management. 3.4 Nuxt.js for SSR: Optimized performance and SEO. 4. Svelte: A framework that shifts work from runtime to compile time. Key advantages: 4.1. No Virtual DOM: More efficient reactivity. 4.2. Simplified Syntax: Less boilerplate compared to React or Angular. 4.3 SvelteKit: Framework for building optimized applications.

Front End Development tools use at ATRI are: 1. Package Managers: NPM (Node Package Manager), Yarn (Fast, reliable package manager) and PNPM (Efficient dependency management) 2. Module Bundlers 2.1 Webpack: Optimizes assets (CSS, JS, images) and supports hot module replacement. 2.2 Parcel: Zero-config bundler for fast builds. 2.3 Vite: Modern, fast development server with native ES modules. 3. Task Runners and Automation Tools 3.1 Gulp: Automates tasks like CSS preprocessing and image optimization. 3.2 Grunt: JavaScript task runner for automation. 4 Code Editors and IDEs 4.1 Visual Studio Code (VS Code): Rich extensions and built-in Git. 4.2 WebStorm: JetBrains' powerful JavaScript IDE. 4.3 Sublime Text: Lightweight, fast text editor. 5. Version Control Systems 5.1 Git: Distributed version control system. 5.2 GitHub/GitLab/Bitbucket/GitTea: Cloud-based repositories for collaboration.

1. RESTful APIs 1.1 HTTP methods (GET, POST, PUT, DELETE) for CRUD operations. 1.2 Tools: Axios, Fetch API, Postman 2. GraphQL 2.1 Query language for APIs with more flexibility than REST. 2.2 Tools: Apollo Client, Relay 3 WebSockets 3.1 Enables real-time bidirectional communication. 3.2 Tools: Socket.io, WebRTC 4. gRPC 4.1 High-performance RPC framework. 4.2 Tools: Protocol Buffers (protobuf), gRPC-Web

1. Content Security Policy (CSP): Prevents XSS attacks. 2. CORS (Cross-Origin Resource Sharing): Restricts unauthorized API requests. 3. JWT (JSON Web Tokens) & OAuth: Secure authentication. 4. Data Encryption: TLS/SSL implementation.

1. Front End Unit Testing technologies Jest: Popular JavaScript testing framework. Mocha & Chai: Flexible testing solutions. 2. End-to-End Testing Cypress: Modern E2E testing framework. Selenium: Automates browser testing. 3. Debugging Tools Chrome DevTools: Debugging and performance monitoring. React Developer Tools: Inspects React components. Redux DevTools: Debugs Redux state changes.

Front End Deployment technologies include: CI/CD Pipelines: GitHub Actions, GitLab CI, Jenkins Hosting Platforms: Vercel, Netlify, AWS Amplify Docker & Kubernetes: Containerization and orchestration