Introduction

Understanding the communication between FE & BE

Request-Response Cycle

Helping Hands in the BackEnd World

BackEnd Frameworks:

So BackEnd Frameworks are used to make the code modular, easy and readable. Some of the popular Frameworks are:

• JavaScript → ExpressJs

• Python → Python Django

• Ruby → Ruby on Rails

• Java → Java Spring

Packages:

These are the codes that we use that other people have written to make our life easier.

• mathjs → Calculation

• mongodb → Talking to the database

• express-session → User login and authentication

Package Mangers:

Package managers as the name suggests manages these packages.

• npm → JavaScript

• pip → Python

• bundler → Ruby

• Maven → Java

DataBase

This helps us to store and manages data.

• mySql

• PostGress

• MongoDB

Request-Response Cycle

What does ‘request’ signifies when we say frontend requests to backend?

So from frontEnd there can be many types of request to the backend:

• Get (retrieve the order)

• Post (add the order in the database)

• Delete (delete a product info in the database)

• Put (update an order info in db)

This list of all the type of request that the backend allows is called an API

Application Programing Interface (API)

Most important concept of backend programing. If you send a request that is not allowed by the API, the backend will respond with an error

REST API

REST → Representational state transfer

This is a naming convention on using the different types of request with the url path we want.

API + REST = REST API

Server Infrastructure

IaaS

Infrastructure as a Service

Instead of buying more computers to process and store data companies now rent the computers/servers from a cloud provider like AWS, Azure, GCP

This is also known as IaaS

Virtual Machine

The rented computer/server is called a virtual machine.

Load Balancer

If a single VM is facing a lot of traffic then the Load Balancer will come in place and will distribute the requests coming on the VM to different VMs

Here you can see that the load balancer is diverting the requests to different servers.

but we will still have a problem here, we will have to create multiple VMs and managing them is a task. Here comes the concept of a service known as PaaS

PaaS

Platform as a Service → This allows us to upload our backend code to a PaaS provider and they will manage all the VMs etc for us.

• AWS Elastic BeanStalk for AWS

• App Engine for GCP

• App Service for Azure

MicroServices

Our backend can be divided into different backends called as microservices.

Here as you can see Twilio is a third party application which is used instead of our own Inhouse MicroService. These type of service is called as SaaS (software as a service)

SaaS

When a companies provides a backend and an API which a company from outside can utilize this is called SaaS

Additional Technologies

Our Primary Database is busy running our site hence we need to utilize different technologies to perform different tasks

Store and Load User Uploaded images

• AWS S3

• AWS Cloudfront

Primary database is not good for storing the image so we use a blob Store like AWS S3 or CDN like AWS Cloudfront to store and load user uploaded images

Text Search

• Elasticsearch

To improve performance

• Redis (Caching)

Data Analytics

• Snowflake (Analitical Database)

Schedule a task for later

• RabbitMQ

Thanks for reading. Please drop your questions in the comments! Thankyou