For JavaScript programmers, what technologies should they master to thrive in their careers?

For JavaScript developers, mastering the following technologies can make their career smoother and more successful:

1. Deep Understanding of JavaScript: Have a profound comprehension of JavaScript's core concepts, including variable declarations (var, let, const), functions (including arrow functions), scope and closures, asynchronous programming (callbacks, Promises, async/await), and object-oriented programming (prototypes, inheritance, classes, etc.).

2. DOM Manipulation and Browser APIs: Understand and be proficient in using JavaScript's DOM manipulation and browser APIs, including HTML, CSS, and browser storage. This will help you better manipulate webpage elements and enhance user experience.

3. Node.js: Node.js is a server-side runtime environment for JavaScript, allowing you to write server-side code using JavaScript. Mastering Node.js and its related ecosystem (such as Express, Koa frameworks) will enable you to build full-stack applications.

4. Front-end Performance Optimization: Understand the principles and methods of front-end performance optimization, including reducing HTTP requests, compressing resources, leveraging caching, code splitting, and lazy loading. This will help you improve web application loading speed and user experience.

5. Front-end Testing: Master the principles and methods of front-end testing, including unit testing, integration testing, end-to-end testing, etc. Learn to use testing frameworks (such as Jest, Mocha) and testing tools (such as Karma, Cypress) to improve code quality and maintainability.

6. Front-end Engineering: Understand the principles and methods of front-end engineering, including build tools (such as Webpack, Rollup), code style checking (such as ESLint), version control (such as Git), etc. This will help you increase development efficiency and reduce the complexity of team collaboration.

7. Front-end State Management: Familiarize yourself with and master front-end state management libraries like Redux or MobX. These libraries can help you better manage states between components, improving your application's maintainability and scalability.

8. Code Protection: As JavaScript code is openly transparent, it is crucial to master JavaScript code protection techniques. JS obfuscation and encryption can protect your code from unauthorized access and modification, safeguarding your intellectual property and code security. Be familiar with and proficient in using common JavaScript obfuscation tools (such as JShaman, JS-Obfuscator).

By mastering these technologies, JavaScript developers can continuously enhance their skills and achieve greater success in their careers.