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What is AWS shared responsibility model?

AWS cloud introduces the shared responsibility model for the developer to understand what area people should be aware of when they use AWS cloud. AWS shared responsibility model has two major parts: AWS responsibility for Security of the Cloud and Customer responsibility for Security in the Cloud.

AWS responsibility:

AWS takes care of the infrastructure that provides the service to the customer. For instance, Global infrastructure, physical data center, Edge locations.

Customer responsibility:

Customers need to take care of how they are going to use those services. For instance, encryption of customers’ data, employee access management, network monitoring.

Explain the shared responsibility model to a 5-year-old:

Here is a simple analogy for…

In this article, you will learn how to use a simple tool to crack the wifi password.

Be aware that you are not permitted to make commercial hacking behavior from this article. This article is only used for educational purposes.

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Wifi introduction:

Wifi stands for Wireless Fidelity, which is a generic term that refers to IEEE802.11 standard for Wireless Local Networks or WLANs. Wifi uses radio technology to send and receive data from point to point. There is three common Wifi standards:

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What is express.Router class?

We can use the Router class to create a modular and mountable route handler. When we create a Router instance to define other middleware or mounts the router module to the application.

Below is an example to create a Router instance:

var router = express.Router()

router.get(‘/’, function (req, res) {

res.send(‘ Hello Express’);


To mount the other router module, we can use the require keyword:

var app = require(‘./expressWeb’)

app.use(‘/expressWeb’, app)

When the user access the route: http://localhost/express. It will go to expressWeb file to look for the default router.

Writing middleware for use in Express apps.

What is Middleware?

In the Express framework, Middleware functions can call the multiple middlewares in the stack…

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Global Infrastructure

AWS provides several infrastructures within AWS Regions and Availability, which can help the user achieve lower latency and high throughput compared to On-premises data center. There are more than 77 availability zones with over 24 Regions around the world. The user can deploy their application into different Regions since each Region is wholly isolated from the other. In this way, users can get higher fault tolerance and stability.

For instance, the company can easily switch the application traffic into different Regions If the application was deployed into two different Regions to provide an uninterruptible browser experience for users.

Global service V.S. Region service

Following the…

There are several ways to serve static files in Express.

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built-in function: static

We can use express.static built-in middleware function in Express to let users access those files.

The Function is like this:

express.static(root, [options])

The root argument specifies the directory from the server.

For example, if you want to let your homepage folder be one of the routes, you can use app.use(express.static(‘homepage’)); Thus, you can access your homepage file using the URL below: http://localhost:3000/homepage.html.


Express will call the express.static middleware functions in order base on the file. …

  1. Open your VScode and navigate to the folder location that you want to submit the assignment.

After navigating to the right folder, click “Select Folder button”

WordPress is a popular content management system. The system written in PHP and use MySQL as their database. AWS is one of the biggest cloud industry provider. In this post, you will learn how to combine these two amazing tool together.

To host WordPress, we need a server and database. In this example, we are going to create a EC2 instance for our server and Aurora MySQL for the database service.

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In this post, you will follow the step below:

  1. Create two Security Groups, one is Web-DMZ and another one is RDS-launch, under default VPC.
  2. Create a role to allow EC2 instance to have access to S3.
  3. Create an…

Routing means it determines how an application responds to client request to specific URI or path including HTTP request method.

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The basic structure of Route following the structure below:

app.METHOD(path, handler)


app is an instance of express.

METHOD is a HTTP request, including get, post, delete.

Path is a file path on the server side.

Handler is a function executed when the path is matched. In this function, it will return the HTML file or JSON formatted data back to user.

The basic route will be like this:

app.get(‘/’, (req, res)=>res.send(`Hello Express`))

When user enter / directory on their browser, it will execute the function (req…

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What is the MEAN stack?

Mean Stack is a solution stack for building dynamic websites and web applications. All the components of the mean stack are written in JavaScript and TypeScript for both server-side and client-side. Mean stack build on web application presentation layer no contains an operating system layer.

MEAN stack components:

MongoDB: mongo DB is a NoSQL database, it uses Binary JSON documents with the schema.

Express.js: it is a popular web application framework package for Node.js.

Angular: It is a web application framework to build a client-side application based on TypeScript.

Node.js: Node.js is an application runtime environment for the MEAN stack.

How Mean stack components communicate with each other?

Recently, I got a lot of questions asking about what type of role should I choose to be my career path. Here is the basic standard for you.

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What is Front-end developer?

You need to know:

1. how to use HTML, CSS, JavaScript

2. how to use JavaScript libraries and framework.

3. how to use build tools including npm, webpack.

You will use these knowledges on:

1. build complex user interfaces.

2. build reusable UI components.

3. user input validation.

4. communication with backend.

5. UX tools including PWAs, and hot reload.

What is backed developer?

You need to know:

1. how to use server side language like…

Yu Che Liu

Java Full stack developer | Google Android Associate developer certified | CompTIA Linux + certified | Teaching Assistant |

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