Today, from social media platforms to e-commerce websites, web applications power a wide range of services. There are numerous benefits of having a functional web application for your business, which makes web application a necessity for the current era.

But have you ever wondered how your favourite websites work behind the scenes? What makes them tick? To get the answers to these questions and to leverage the maximum usage of a website, you must know about the various components of a web app architecture—the secret behind your go-to apps and sites.

This article will demystify web application architecture by critically analysing its key components. We’ll also explore how web application architecture works and the layers and different patterns of it.

But first, let’s begin with the introduction of web application architecture and understand why it is crucial.

Let’s get going!

What is Web Application Architecture?

The web application architecture is a structural design that explains the interconnection between various components such as applications, databases, and middleware systems and their interaction with each other. It helps establish a communication channel between the server and the client.

The web application architecture encompasses the arrangement of various components, modules and technologies that work together to deliver the functionality of a web application. It determines how these components interact, how data flows within the application, and how the application handles user’s requests and responses.

web application development service

Analysing the key components of web application architecture one-by-one.

Key Components of Web Application Architecture

Every component of the architecture design of a web application plays a crucial role in functionalities, performance, security, scalability and user experience offered to your web app audiences. These components help in building the digital constitution of your web application.

There are mainly two components of web application architecture. These are:

User Interface App (Client Side) Components

The client side constitutes the user-interface components, also known as the “frontend” is relevant to the end-users of the app. This includes all the displayed elements on the client’s device, including the dashboard, images, texts, menus, logs and other parts of the UI.

These are user-centric components oriented to every action the user takes while navigating the web app. The client-side feature includes:

  • User Interface (UI) – The visible part of the application that users interact with. It includes HTML for content structure, CSS for styling, and JavaScript for interactivity.
  • Web Browser – The software end-users use to access and interact with web applications.

Structural (Server Side) Components

Structural components, commonly called the “backend”, perform the primary functionalities of handling and processing the user requests and managing the business logic. It assists in retrieving and displaying the data requested at the client side of the web application.

The server-side component or application layer is typically written using programming languages like Python, Java, Ruby, PHP, and many others. Structural side component includes:

  • Web Server – Handles incoming HTTP/HTTPS requests from clients (web browsers), routing them to the appropriate components and returning HTTP/HTTPS responses

    Some examples of Web Server are Apache, Nginx, and Microsoft IIS.
  • Application Server – Executes the business logic, processes requests, and interacts with a database or other services. It’s responsible for handling the application-specific tasks.
  • Database Server – Stores and manages the application’s data. It can be a relational database (MySQL, PostgreSQL) or a NoSQL database (MonoDB, Redis). They are driven by servers required to run the web application seamlessly.

The structure of a web application can differ based on chosen requirements and technologies. Various architectural patterns such as monolithic, microservices, and serverless provide different methods of organising these components.

The other core components that work together to create a functional and reliable web application includes:

  • Database Management System (DBMS)
    The software that manages and controls the database, including data storage, retrieval, indexing, and security.
  • APIs (Application Programming Interfaces)
    They enable communication and data exchange between different software components within the web application. APIs define how different application parts can interact with each other and external services.
  • Security Components
    Authentication: Verifies the identity of users, ensuring that only authorised individuals can access specific parts of the application.
    1. Authorisation: It determines what actions or resources authenticated users can access or manipulate.
    2. Encryption: Secures data transmission between the client and server, preventing eavesdropping and tampering.
    3. Firewalls: Protect the application from unauthorised access and attacks.
    4. Security Tokens and Cookies: Manage user sessions and maintain user authentication across requests.
  • Caching
    Stores frequently accessed data or resources in memory to reduce the load on the server and improve application performance.
  • Load Balancers
    Load balancers distribute incoming web traffic across multiple servers to ensure high availability, scalability, and load distribution. They help prevent server overload and provide redundancy, enhancing the overall performance and reliability of a web application.
  • Monitoring and Logging
    They are the tools and practices for tracking the web application’s performance, health, and security. Monitoring tools collect data, and logs capture events, errors, and diagnostics for analysis and troubleshooting.

Architecture Diagram for Web Application

Architecture Diagram for Web Application

[Source: Medium]

How Does Web Application Architecture Work?

The web application architecture defines how the various components collaborate and ensures that the application remains scalable and secure to meet user requirements. This iterative process repeats for each user interaction with the web application.

To understand how web application architecture works, let’s break down the process step by step:

Step-by-step process of web application architecture
  • User Interaction
    A user interacts with a web application by opening a web browser, entering a URL, or clicking a link or bookmark. This request made by users is sent to the web server hosting the application.
  • Web Server Processing
    The web server receives the user’s request via HTTP (Hypertext Transfer Protocol). It may employ a load balancer to distribute requests evenly across multiple application server instances for scalability and fault tolerance.
    The web server further routes the user request to the appropriate component, often the frontend application server or a reverse proxy.
  • Frontend Processing (Client-Side)
    If the request involves rendering a web page, the frontend application (written in JavaScript, HTML, or CSS) processes the request.
    The front-end application may retrieve data from the backend, external APIs, or databases via API calls. It generates the HTML, CSS, and JavaScript necessary to render the web browser’s user interface (UI).
  • Backend Processing (Server-Side)
    The backend application server handles the request for application-specific logic or data retrieval. It may interact with databases, external services, or other components to fetch data, perform calculations, or execute business logic.
    After processing, it sends the response data back to the frontend application, often in JSON or XML format.
  • Database Interaction
    If required, the backend server interacts with the database server to read or write data. The database management system (DBMS) processes queries, retrieves or updates data, and sends results to the application server.
  • Response Generation
    The frontend application receives data from the back end and generates the final HTML, CSS, and JavaScript required for rendering the UI in the user’s web browser.
  • User Interface Rendering
    The user’s web browser receives the HTML, CSS, and JavaScript and renders the web page on the screen. JavaScript can further enhance interactivity by responding to user actions or making additional requests to the server via APIs.
  • User Response
    The user interacts with the web page, potentially submitting forms, clicking buttons, or navigating to other pages. These interactions trigger new HTTP requests, which are sent back to the web server. Thus, repeating the cycle.
  • Security and Authorisation
    Various security measures, including authentication and authorisation, are applied throughout the process to protect user data and the application.
    Encryption mechanisms like SSL/TLS are applied to secure data in transit to create a safe environment for the user and server.

Web Application Architecture Layers

Web application architecture typically consists of multiple layers for specific functions and tasks. These layers help organise and separate concerns, making the application more maintainable and scalable.

  • Presentation Layer (UI Layer)
    This top layer deals with user interface (UI) and user interaction. It includes web pages, user interfaces, and client-side code (HTML, CSS, JavaScript) responsible for rendering and displaying content to users.
    The presentation layer interacts with the user through web browsers or mobile app interfaces.
  • Application Layer (Logic Layer)
    The application layer contains the core business logic and application-specific functionality. It processes user requests, handles business rules, an orchestrates data flow and operations.
    In many cases, the application layer also includes APIs that allow external systems or clients to interact with the application.
  • Data Access Layer (Persistence Layer)
    This layer interacts with data sources like databases, file systems, or external APIs. It handles data retrieval, storage, and manipulation operations.
    The data access layer often uses database management systems (DBMS) for relational or non-relational data storage.
  • Security Layer
    The security layer is integrated throughout the architecture, but it’s important to highlight it as a distinct layer. It manages authentication and authorisation, ensuring the access of certain parts of the application or performing specific actions to only authorised users.
    Security measures such as data encryption are adopted to protect data, and communication is also a part of this layer.
  • Infrastructure Layer (Deployment Layer)
    The infrastructure layer includes the underlying hardware and software infrastructure that supports the application’s execution. It involves server hosting, load balancing, cloud services, and network configurations.
    This layer includes infrastructure components like web servers, application servers, and databases.

Types of Web Application Architecture

Web application architecture can take on various forms or types, each with its characteristics, advantages, and disadvantages. The choice of architectural pattern depends on the application’s specific needs, goals, and constraints.

Some of the most prevalent web application architecture types are:

Types of web application architecture

1. Monolithic Architecture

In monolithic architecture, all application components, including user interface, business logic, and data access, are tightly integrated into a single codebase and runtime.

Developing and deploying this architecture initially is relatively simple, making it suitable for smaller applications. However, as the application grows, monolithic architectures can become harder to maintain and scale, leading to challenges in development and deployment.

2. Client-Server Architecture

The client-server setup splits the application into two core components: a client, dealing with the user interface and interactions, and a server, handling data processing and business logic.

This architecture allows for a clear separation of concerns, making it easier to maintain and scale as needed. The common variations of client-server architecture include:

  • Two-tier (client and server), and
  • Three-tier (client, application server, and database server) architectures.

3. Serverless Architecture

Serverless architecture abstracts server management entirely from the developer. Developers on the other hand write code in functions or microservices, and the cloud provider is responsible for managing server provisioning, scaling, and execution in this form of architecture.

serverless web app architecture

[Source: ClickIt]

Chatbot CI Pipelines, live streaming, IoT sensor messages, Multimedia Processing etc. are some of the serverless computing use cases. You can perform serverless computing using API Step Functions, AWS Lambda and API Gateway in a microservice architecture.

Serverless architectures are cost-effective and highly scalable, as resources are allocated dynamically. They are well-suited for event-driven applications. However, some serverless applications may require more control over server environments. Hence, they are not suitable for all the web application architecture mechanisms.

  • Progressive Web App (PWA) Architecture
    PWAs are web applications that offer a native app-like experience in web browsers.
    They utilise modern web technologies to provide features like offline access, push notifications, and fast loading times.PWA web application architecture can be built using various patterns, including single-page application (SPA) architecture. The PWA architecture offers a great preposition towards improved user engagements and experience (UX). Hence, PWAs are a perfect match to promote your business.[Also read: Increase Business Engagement and Revenue using PWA Architecture]

Why is Web Application Architecture Important?

Now that we have developed a fair understanding of web application architecture, let’s look at the innumerous benefits it offers.

The various advantages of web app architecture are:

  • Scalability – An effective architecture allows web applications to scale quickly as user traffic and data grow.
  • Performance – A well-designed architecture optimises performance by efficiently managing data retrieval, processing and rendering.
  • Security – Web application architecture plays a pivotal role in safeguarding sensitive user data and protecting against cyber threats.
  • Maintainability – A well-structured architecture makes maintaining and updating the application easier over time.
  • Flexibility and Adaptability – The architecture allows for flexibility in technology choices and future enhancements.
  • Fault Tolerance – Effective architecture includes redundancy and fault tolerance mechanisms to ensure the application remains available despite hardware failures or errors.


In today’s digital arena, understanding web application architecture is vital for building scalable, secure, and efficient web applications for the end-users. By analysing the essential components and architectural patterns of a custom web application development, you can deliver a customer-centric, optimised and cost-effective solution to gain the interest and trust of your customers.

Whether you’re a developer, architect, or simply a curious user, this knowledge will help you comprehend the inner workings of the web applications that power our digital lives.

However, these are complex notions and, thus, require a professional web application development service provider to provide you with the necessary know-how and assistance in developing a highly responsive and functional web app for your business.