Building a Scalable web App on AWS: A Step-by-Step Guide

This content originally appeared on DEV Community and was authored by Daberechi

Introduction

Welcome to my latest project where I dive into the world of cloud computing and scalability! In this article, I'll share my experience building a highly available web application on AWS, leveraging services like Autoscaling, Load Balancing, and more. Whether you're a seasoned developer or just starting out, this project showcases the power and flexibility of AWS in creating robust and efficient web infrastructures. Let's dive in and explore the details of this project!

CREATING VPC

Login to your AWS Management Console
Search VPC and click on it
Click create VPC
Click create VPC and more
Name your VPC (under auto-generate)
Let's leave the default IP address in IPV4 CIDR Block
Select no IPV6 under IPV6 CIDR Block
Select 2 under number of availability zone
Select 2 under number of public subnet
Select 2 under number of private network
Select 1 per AZ under NAT gateway
Select none under VPC endpoint
Click create VPC

LET'S CREATE AUTO SCALING GROUP

In your AWS Management Console, search for EC2 and click on it
Scroll down the menu by your left and click on auto scaling group
Click on create auto scaling
Name your auto scaling
Click on create a launch template

In template version description, put a description of what you want to use the launch template for
Scroll down, and click on recently launched
Scroll down to instance type, and select free tier
If you don't have any key pair, then create a new one. But if you have, select it in your key pair section
Scroll down to network settings
Under firewall (security group), select create security group
Name your security group
Under description, put allow SSH access
Click the drop-down menu under VPC and select the VPC you created earlier
Click on add security group rule
Under type, select SSH
Under source type, select anywhere
Click on add security group rule again
Under type, select custom TCP
Under port range, put the port you want (I put 8080 for this project)
Under source type, I selected anywhere
Click on add security group again,
Under type, select http
the port will automatically be updated (80)
in source type, select anywhere
Click on launch template
After creating, refresh the page
Then under name ( auto scaling group name) put the name you used while creating the launched template
Click the drop-down menu on launch template and select the template you created
Click on next
Click on the VPC drop-down button and select the VPC you created earlier
Under availability zone and subnet, select the two private subnet (private 1 and private 2). This is because we want to deploy our server in a private subnet for security purpose.
Click on next
Select no load balancer
Scroll down and click next
Since we are creating two instances, we will adjust desire capacity to 2
Adjust maximum capacity to 4
Select none under scaling policy
Click next
Click next if you don't want to add notifications
Click next
Click on create auto scaling group
Now go to your EC2 instance and you will see two instances

The two instances generated with auto scaling does not have public IP address. This is because we want to deploy our server in a private subnet.
Since the instances does not have public IP for us to login with, we are going to deploy a Bastion server that we will used to access our instances

CREATING A BASTION SERVER

Go to your EC2 instance
Click on launch instance
Let's name ame it bastion-host
I'm choosing Ubuntu as image
Choose free tier as instance type
Choose your key pair
Select create security group and make sure you see SSH
Click on edit in network settings
Click the VPC drop-down button and select the VPC you created earlier
Click the drop-down button in auto assign IP, and click enable
Click on launch instance

CONNECTING TO OUR SERVER PRIVATELY THROUGH OUR BASTION HOST

Open your terminal ( either AWS cloud shell, AWS CLI, Powershell, Mobaxterm)
If you are logging in through AWS cloud shell, AWS CLI or Powershell, type ssh -i your key pair.pem Ubuntu@your bastion server public IP
If you are logging in through mobaxterm, check my previous post to see how to login with mobaxterm
Once you are logged in copy your key pair to your bastion host by typing scp -i /path/to/your/keypair.pem Ubuntu@bastion host public IP:~/.ssh/ enter (e.g scp -i/user/downloads/aws-login.pem Ubuntu@54.90.58:~/ssh/
Type yes ( are you sure you want to continue connection)
Type sudo apt update
Type ls (this means list)
Then type ssh -i your key pair.pem Ubuntu@your bastion host private IP, then hit enter ( this shows that you are able to login to your server privately)
Type yes, enter
Go to your browser and type w3 schools HTML basic
Click on HTML basic examples
Scroll down and click on try it yourself
Copy the HTML
Go back to your work, and type vim index.html, hit enter
Paste the HTML
Remove where you see my first heading and place it with my first AWS project ( or anything)
Remove where you see
my first paragraph

remove everything and type:wq! (To save)
Then type python3 -m http.server 8080 hit enter

LET'S CREATE AN APPLICATION LOAD BALANCER

Go to your AWS Management Console and search for EC2
Click on it
Scroll down the menu by your left and click on load balancer
Click on create load balancer
Click on Application load balancer create
Name it

Select internet facing
Select IPV4
Click the VPC drop-down button and select the two availability zone
Click on drop-down button under subnet and select public subnet
Select your security group
Under listener & routing, click on create target group
Select instances
Scroll down to target group name, and name it
Leave the HTTP, put port 8080 or any port you want
Click on next
Select the two instances created with auto scaling. Do no select bastion host instance
Scroll down and click on include as pending
Click on create
Go back to your load balancer
Under listener and routing, leave protocol at HTTP, and port 8080
Click the HTTP drop-down button and select the target group you created
Click on create load balancer
Navigate to your security
Click on one of the EC2 instance id
Scroll down and copy DNS name
Go to your browser and paste it, then hit enter

We come to the end of today's section
See you soon. Bye

This content originally appeared on DEV Community and was authored by Daberechi

Print Share Comment Cite Upload Translate Updates

APA

Daberechi | Sciencx (2025-07-05T11:05:04+00:00) Building a Scalable web App on AWS: A Step-by-Step Guide. Retrieved from https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/

MLA

" » Building a Scalable web App on AWS: A Step-by-Step Guide." Daberechi | Sciencx - Saturday July 5, 2025, https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/

HARVARD

Daberechi | Sciencx Saturday July 5, 2025 » Building a Scalable web App on AWS: A Step-by-Step Guide., viewed ,<https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/>

VANCOUVER

Daberechi | Sciencx - » Building a Scalable web App on AWS: A Step-by-Step Guide. [Internet]. [Accessed ]. Available from: https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/

CHICAGO

" » Building a Scalable web App on AWS: A Step-by-Step Guide." Daberechi | Sciencx - Accessed . https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/

IEEE

" » Building a Scalable web App on AWS: A Step-by-Step Guide." Daberechi | Sciencx [Online]. Available: https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/. [Accessed: ]

rf:citation

» Building a Scalable web App on AWS: A Step-by-Step Guide | Daberechi | Sciencx | https://www.scien.cx/2025/07/05/building-a-scalable-web-app-on-aws-a-step-by-step-guide/ |

Please log in to upload a file.

There are no updates yet.
Click the Upload button above to add an update.

You must be logged in to translate posts. Please log in or register.

Related Posts