Web Application Architecture 2024: Patterns, Elements, All You Need to Know

We often have clients coming to us asking to fix their web application that was developed by another outsourcing company. The most challenging and costly fixes are usually required when the root of the problem lies in a poorly designed architecture. 

It defines the structure of a web application, organizing its components—such as client-side interfaces, server-side logic, and databases—to ensure smooth communication and performance.

“Web application architecture serves as a blueprint that guides the development process, ensuring that every part of the application works together seamlessly. By understanding and optimizing these key components, we help CTOs and CPOs make informed decisions and choose the best architectural solutions for their projects.”

Fundamentals of Web Application Architecture

Client-Server Model

The client-server model is the foundation of most web applications. In this architecture, the client (frontend) is the user interface that interacts with users, while the server (backend) handles data processing, business logic, and database operations. The client sends requests to the server, which responds with the necessary data or actions. This model allows for a clear separation of concerns, making it easier to manage and scale web applications.

HTTP Protocol

The HTTP protocol is the backbone of communication between the client and server in a web application. It operates on a request-response cycle, where the client sends an HTTP request, and the server returns an HTTP response.

Key aspects of the HTTP protocol include:

• Request Methods: GET (retrieve data), POST (submit data), PUT (update existing data), DELETE (remove data).
• Status Codes: Indicate the result of a request, such as 200 (OK), 404 (Not Found), 500 (Internal Server Error).
• Headers: Provide additional information about the request or response, such as content type or authorization.

Understanding these components is essential for developing robust web applications that communicate effectively online.

URL Routing

URL routing is a mechanism that maps URLs to specific actions or resources within the application. It defines how incoming requests are handled and directs them to the appropriate part of the application. For example, a URL like /products/123 might route to a function that retrieves and displays details about a specific product. Effective URL routing ensures that web applications are easy to navigate and maintain, providing a user-friendly experience.

Web Application Architecture Patterns, Explained by ProCoders

We asked our senior solutions architects to explain the patterns that we used depending on the needs of our clients.

Monolithic Architecture

Monolithic architecture is a traditional approach where the entire application is built as a single, unified codebase. All components, including the user interface, business logic, and database access, are tightly integrated.

Advantages:

• Simplicity in development and deployment.
• Easier to manage in small teams or projects.
• Direct communication between components, reducing latency.

Disadvantages:

• Scalability challenges due to the tightly coupled nature of components.
• Difficult to update or modify without affecting the entire application.
• Increased risk of system-wide failures when errors occur.

Microservices Web Application Architecture

Microservices architecture breaks down an application into smaller, independent services, each responsible for a specific function. These services communicate through APIs and are often deployed independently.

Advantages:

• Each service can be scaled independently based on demand.
• Teams can deploy updates to individual services without affecting the whole application.
• Easier to adopt new technologies and make changes to individual services.

Disadvantages:

• Complexity in managing multiple services and coordinating communication.
• Increased overhead in inter-service communication and monitoring.
• Requires robust DevOps practices for effective deployment and maintenance.

SOA (Service-Oriented Architecture)

Service-Oriented Architecture (SOA) is similar to microservices but typically involves larger, more comprehensive services that align with business processes. SOA focuses on reusability and interoperability between services.

Advantages:

• Reusability of services across different applications or business units.
• Interoperability, supporting diverse technology stacks and platforms.
• Strong alignment with business processes, enhancing flexibility and adaptability.

Disadvantages:

• Complexity in implementation and maintenance due to the reliance on middleware.
• Higher overhead in managing services and ensuring seamless communication.
• Dependency on middleware for service integration, which can add latency.

Serverless Architecture

Serverless architecture allows developers to build and run applications without managing the underlying server infrastructure. The cloud provider automatically scales resources based on demand, and developers are charged only for the actual compute time used.

Advantages:

• No server management required, reducing operational overhead.
• Automatic scaling to handle varying loads efficiently.
• Cost efficiency: Pay only for the compute resources used.

Disadvantages:

• Limited to the features and services provided by the cloud vendor.
• Functions may have a delay when invoked after being idle.
• Limited control over the backend environment and infrastructure.

Now, let’s talk about the frontend and backend architectures separately.

Frontend Architecture of Modern Web Applications

Single-Page Applications (SPA)

Single-Page Applications (SPAs) load a single HTML page and dynamically update content as users interact with the app, without requiring full page reloads. This provides a smoother user experience, similar to native apps. Popular frameworks for SPAs include React, Angular, and Vue. SPAs are ideal for interactive web applications like social media platforms and dashboards.

Multi-Page Applications (MPA)

Multi-Page Applications (MPAs) consist of multiple pages loaded separately from the server. Each user action that navigates to a new page triggers a request to the server for a full HTML page. MPAs are suitable for content-rich websites like e-commerce sites and blogs, where SEO and independent page navigation are important.

Progressive Web Applications (PWA)

Progressive Web Applications (PWAs) combine web and native app features, offering offline capabilities, push notifications, and home screen installation. PWAs use service workers to cache resources, providing a reliable user experience even with limited internet connectivity, making them a versatile choice for a wide range of applications.

Backend Architecture of a Web Application

MVC (Model-View-Controller) Architecture Pattern

The MVC pattern separates an application into three components:

• Model: Manages data and business logic.
• View: Displays the user interface.
• Controller: Handles input and updates the model or view.

This separation helps organize code and improve maintainability.

RESTful API Design

RESTful APIs use standard HTTP methods (GET, POST, PUT, DELETE) for communication between the client and server. They are stateless, ensuring each request is independent, which simplifies scaling and development.

GraphQL

GraphQL allows clients to request only the data they need, reducing bandwidth usage and improving performance. Unlike REST, GraphQL provides a flexible, efficient way to interact with APIs, particularly for complex applications.

Databases in Web Architecture Design

Relational Databases

Relational databases like MySQL and PostgreSQL store data in structured tables and use SQL for querying. They are ideal for applications requiring complex queries and data integrity.

NoSQL Databases

NoSQL databases like MongoDB (document store) and Redis (key-value store) offer flexibility and scalability for handling large volumes of unstructured data, making them suitable for real-time applications.

Database Scalability

Scalability strategies include:

• Vertical Scaling: Adding resources to a single server.
• Horizontal Scaling: Distributing data across multiple servers.
• Sharding: Partitioning data across servers.
• Replication: Duplicating data for high availability.

Choosing the right database and scalability approach is key to maintaining performance as the application grows.

Communication Protocols in Architecture of Web Application

REST (Representational State Transfer)

REST is a set of principles for designing networked applications, relying on stateless communication and standard HTTP methods (GET, POST, PUT, DELETE) to manage resources identified by URLs. It’s simple, scalable, and widely used for web APIs.

WebSockets

WebSockets provide real-time, two-way communication between a client and server over a single connection, unlike the request-response model of HTTP. This is ideal for applications needing instant updates, such as chat apps or live feeds, reducing latency and improving performance.

gRPC

gRPC is a high-performance RPC framework using HTTP/2 and Protocol Buffers. It supports bidirectional streaming and is efficient for communication between microservices, offering better performance than REST through its compact, binary format.

Caching and Performance Optimization in Web Application Structure

Caching Strategies

Caching improves performance by storing data:

• Client-side: In the browser, reducing server requests.
• Server-side: On the server, speeding up responses.
• CDN: Geographically distributed caching to reduce latency.

Load Balancing

Load balancing distributes traffic across multiple servers to prevent overload and improve reliability. Common techniques include Round Robin, Least Connections, and IP Hash.

Content Delivery Networks (CDN)

CDNs use distributed servers to deliver content closer to users, reducing latency and improving load times, which are crucial for globally distributed applications.

Deployment and Scaling

Deployment Pipelines

Continuous Integration/Continuous Deployment (CI/CD) pipelines automate the build, testing, and deployment of web applications. They streamline the development process, ensuring that new code is consistently integrated, tested, and deployed to production with minimal manual intervention.

Containerization

Containerization, using tools like Docker and orchestration platforms like Kubernetes, encapsulates applications and their dependencies into containers. This approach provides consistency across environments, simplifies deployment, and enhances scalability by allowing microservices to run independently.

Cloud Hosting

Cloud hosting platforms such as AWS, Azure, and Google Cloud offer scalable infrastructure and services for deploying web applications. These platforms provide on-demand resources, automated scaling, and global distribution, enabling high availability and performance.

Monitoring and Logging

Application Monitoring

Tools like Prometheus and New Relic are essential for monitoring the performance and uptime of web applications. They provide real-time insights into application behavior, helping teams identify and resolve issues quickly.

Logging

Logging is crucial for debugging, auditing, and monitoring applications. The ELK stack (Elasticsearch, Logstash, Kibana) is a popular solution for collecting, analyzing, and visualizing logs to ensure smooth operation and quick troubleshooting.

Error Handling

Effective error handling involves capturing errors, logging them appropriately, and providing meaningful feedback to users. Best practices include using try-catch blocks, custom error messages, and tools like Sentry for error tracking and reporting.

Security Considerations

During our decade-long experience building applications, we at ProCoders have encountered several considerations in terms of security. So, let us share our insights.

Authentication and Authorization

Authentication confirms user identity (using OAuth or JWT), while authorization controls access to resources (using RBAC or ABAC). These methods ensure secure and appropriate access to application data.

HTTPS and SSL/TLS

HTTPS secures data transfer over the internet using SSL/TLS encryption, protecting against eavesdropping and man-in-the-middle attacks, ensuring secure client-server communication.

Common Security Threats

Key threats include:

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• SQL Injection: Inserting malicious SQL into input fields.
• XSS (Cross-Site Scripting): Injecting scripts into web pages.
• CSRF (Cross-Site Request Forgery): Trick users into executing unwanted actions.

Mitigation involves input validation, prepared statements, security headers, and anti-CSRF tokens.

ProCoders Experience with Modern Web App Architectures

Real Estate Project – NDA

By making strategic choices in web architecture, ProCoders successfully delivered a high-performance web application for a Nordic real estate company. By using VueJS for a responsive and dynamic frontend and PHP/Laravel for a robust backend, ProCoders ensured seamless integration and efficient handling of complex functionalities like automated contract generation and tenant management. 

Their decision to provide a dedicated team led by a senior solution architect enabled modular development, rapid deployment, and scalability. ProCoders also implemented secure practices to protect sensitive information, emphasizing security and data privacy, demonstrating a comprehensive approach to building a reliable, scalable, and secure web application tailored to the client’s needs.

Modern App Application Architecture: Conclusion

We at ProCoders have highlighted for us some of the web application architecture best practices; they include choosing the right architectural pattern, using modern tools like microservices and containerization, focusing on security, and using effective monitoring and scaling strategies.

The future of web application architectures is moving towards more distributed, modular systems with a focus on scalability, security, and performance. Trends like edge computing, micro frontends, and API-first development are set to shape the landscape in the coming years.