Concepts

MFE vs Monolithic

This article on Martin Fowler’s website, discusses the challenges of frontend development at scale and introduces a trend of breaking down monolithic frontend architectures into smaller, manageable components. It explores the benefits, costs, and implementation options of this approach, using a detailed example application to illustrate its effectiveness in improving collaboration and efficiency among multiple development teams.

Micro Frontends offer several advantages, including:

1. Independent Development and Deployment: Micro Frontends allow different teams to work on separate parts of the user interface independently. Each micro frontend can be developed, tested, and deployed autonomously.

2. Technology Diversity: Teams can choose the best-suited technologies for their specific micro frontend, enabling the use of diverse frameworks and tools within a single application.

3. Scalability: Scalability is more granular, as teams can scale individual micro frontends based on demand, providing better resource utilization.

4. Isolation and Fault Tolerance: Micro Frontends are isolated, reducing the impact of failures or changes in one part of the application on others. This enhances fault tolerance and makes it easier to troubleshoot issues.

5. Incremental Updates: Updates and enhancements can be made incrementally, reducing the risk associated with large-scale changes. This facilitates more frequent releases and quicker time-to-market.

6. Team Autonomy: Teams have greater autonomy, allowing them to choose their development processes, tools, and release cycles, leading to increased ownership and responsibility.

7. Reuse and Composition: Micro Frontends can be reused across different projects or composed to create new user interfaces. This promotes code reusability and modular design.

8. Improved Collaboration: Micro Frontends enable multiple teams to collaborate more effectively, as they can work on different parts of the application simultaneously without interfering with each other.

9. Easier Maintenance: Maintenance becomes more manageable, as changes to one micro frontend are less likely to impact others. This makes it easier to update and evolve the application over time.

10. Flexibility in Development Lifecycle: Different teams can follow their own development lifecycles and release schedules, allowing for flexibility in managing feature releases and updates.

While micro frontend architecture can offer several advantages, it’s important to be aware of potential pain points and challenges associated with its implementation.

Some of the common pain points include:

1. Complexity of Orchestration: Coordinating multiple micro frontends can introduce complexity in terms of orchestration. Managing the communication and synchronization between different parts of the application can be challenging.

2. Consistent UI/UX: Ensuring a consistent user interface and user experience across micro frontends can be a significant challenge. Achieving a cohesive design and consistent branding may require additional effort.

3. Build and Deployment Complexity: As each micro frontend can have its own build and deployment process, managing the entire system’s build pipeline can become complex. Coordinating versioning and releases across different parts of the application may require careful planning.

4. Cross-Cutting Concerns: Implementing cross-cutting concerns such as authentication, authorization, and error handling consistently across micro frontends can be challenging. Ensuring that these concerns are properly addressed in each module is essential for the overall system’s integrity.

5. Data Sharing: Sharing data between micro frontends can be problematic. Handling data consistency and synchronization becomes a challenge, especially when different parts of the application need access to shared state or data.

6. Learning Curve: Adopting a micro frontend architecture may introduce a learning curve for development teams. Team members need to understand how to structure and communicate between micro frontends, which may be a departure from traditional monolithic development.

7. Performance Overhead: The use of multiple frameworks and libraries can introduce performance overhead. The client-side rendering of multiple frameworks may impact page load times and user experience, particularly if not managed carefully.

8. Tooling and Ecosystem: Some micro frontend architectures may have limited tooling or may require specialized tools for development, testing, and debugging. A well-established ecosystem is crucial for the success of a micro frontend approach.

9. Increased Network Requests: Loading multiple micro frontends may result in increased network requests, impacting performance. Optimizing for efficient loading and reducing unnecessary dependencies is crucial.

10. Versioning and Compatibility: Managing versioning and ensuring compatibility between different micro frontends can be challenging. Changes in one micro frontend may impact others, necessitating careful version control.

Despite these challenges, many organizations find value in micro frontend architectures when properly implemented. Addressing these pain points requires careful planning, adherence to best practices, and continuous improvement in the development and deployment processes.

A Micro Frontend Orchestrator like fusionize.dev, is a tool that manages the integration, coordination, and communication between individual micro frontends in a micro frontend architecture. It will address the aforementioned challenges, managing both complexity and associated overhead.

Decoupled Architecture

A decoupled architecture, also known as a loosely coupled architecture, is an approach to system design where components or modules are designed to operate independently with minimal dependencies on each other. This architectural style promotes flexibility, scalability, and ease of maintenance. Decoupling allows changes to be made to one component without affecting the entire system, making it easier to update, modify, or replace individual parts without disrupting the entire application.

Key characteristics and principles of a decoupled architecture include:

1. Modularity: The system is divided into smaller, independent modules or components. Each module has well-defined responsibilities and interfaces, allowing for easy substitution or modification without affecting other parts of the system.

2. Interoperability: Decoupled systems often use standardized communication protocols and interfaces to enable interoperability between components. This facilitates the integration of new components or services.

3. Independence: Components operate independently, and changes to one component do not impact the behavior of others. This independence allows for greater flexibility in development and maintenance.

4. Flexibility and Agility: Decoupled architectures are more adaptable to change. Teams can work on different components simultaneously, and updates or changes can be rolled out more easily without requiring a complete system overhaul.

5. Scalability: The modular nature of a decoupled architecture makes it easier to scale specific components or services based on demand. This is especially important in distributed systems and cloud-based architectures.

6. Reduced Maintenance Complexity: With a decoupled architecture, maintenance tasks become more straightforward. Updating or replacing a module can be done without affecting the entire system, reducing the risk of unintended consequences.

7. Technology Neutrality: Components within a decoupled system can be built using different technologies and programming languages, as long as they adhere to common communication standards. This allows for greater flexibility in technology selection for different parts of the system.

8. Improved Testability: Decoupled systems are often easier to test because individual components can be tested in isolation. This makes it simpler to identify and fix issues within specific modules.

Decoupled architectures are commonly employed in various domains, including software development, microservices architectures, and service-oriented architectures (SOA). While there are benefits to decoupling, it’s essential to strike a balance, as overly decoupled systems may introduce challenges related to communication overhead and increased complexity in certain scenarios. The choice of architecture depends on the specific requirements and goals of a given project.

Composition

Microfrontend composition refers to the process of combining individual micro frontends, developed independently by different teams, to create a cohesive and complete user interface. In a micro frontend architecture, where the user interface is broken down into smaller, autonomous components, composition becomes essential for delivering a seamless and integrated user experience. composition can be achieved through various approaches, and the choice often depends on the specific requirements and characteristics of the project. Here are some common types of microfrontend composition:

• Build-Time Composition: During the build process, individual micro frontends are compiled, and the resulting artifacts are combined into a single bundle. This bundle is then deployed and served to users. This approach simplifies runtime composition but may limit flexibility.

• Run-Time Composition: Run-time composition involves combining micro frontends dynamically at runtime based on user interactions or other contextual factors. This approach offers greater flexibility but may introduce additional complexity.

• Server-Side Composition: In this approach, the composition of micro frontends occurs on the server side before the content is sent to the client. The server is responsible for combining the individual micro frontend components into a complete HTML page, which is then delivered to the browser.

• Hybrid Composition: Some projects may use a combination of the above approaches, selecting the most suitable method for different parts of the application or based on specific use cases. For example, server-side composition might be used for initial rendering, while client-side composition is employed for subsequent interactions.

• IFrame Integration: In certain scenarios, micro frontends can be embedded within iframes on a page. Each iframe corresponds to a different micro frontend, allowing for isolation and independence. Communication between iframes is managed through established mechanisms like postMessage.

The choice of composition type depends on factors such as the project’s architectural goals, performance considerations, development team preferences, and the need for dynamic updates. The flexibility offered by micro frontend architectures allows teams to select the most suitable composition strategy for their specific use case.

Build Time Composition

Build Time Composition assembles Fragments at build time, not at client or server. bit.dev is a powerful build system for micro frontends build time composition. Some advantages of build time composition:

• Optimized Performance: Combining micro frontends into a single bundle at build time allows for optimizations such as tree shaking and code splitting. This results in smaller, more efficient bundles that contribute to faster load times and improved overall performance.

• Predictable Deployment The composed application is deployed as a single unit, simplifying the deployment process. This predictability can reduce the likelihood of deployment-related issues and make rollbacks easier if needed.

While Build-Time Composition offers certain advantages, it also comes with some disadvantages that should be considered when choosing this approach for a micro frontend architecture. Here are some potential drawbacks:

• Lack of Dynamism: Build-Time Composition is static, meaning that the composition structure is determined during the build process. This lack of dynamism can be a limitation for applications that require dynamic updates or frequent changes in the composition.

• Limited Flexibility: Changes to the composition structure often require a rebuild of the entire application. This can limit the flexibility to experiment with different configurations or adapt to evolving requirements without incurring significant development overhead.

• Resource Overhead: The composed application is delivered as a single bundle, and users must download the entire bundle even if they only interact with a subset of micro frontends. This can lead to unnecessary resource overhead, especially for larger applications.

• Complexity for Large Applications: In large-scale applications with numerous micro frontends, managing the composition and dependencies at build time can become complex. The overall architecture may become harder to understand and maintain.

• Challenges in Versioning: Coordinating version updates across multiple micro frontends can be challenging. If different micro frontends have varying release cycles or dependencies, ensuring compatibility and consistent versions becomes more complex.

• Reduced Development Autonomy: Teams working on different micro frontends may have less autonomy, as changes in one micro frontend can impact the entire application and require coordination with other teams.

• Scaling Issues: As the application scales, the benefits of Build-Time Composition may diminish, and the approach may encounter scalability issues, particularly if the build process becomes a bottleneck.

When considering Build-Time Composition, it’s crucial to evaluate these disadvantages against the specific requirements and goals of the project. Depending on the nature of the application and the development team’s priorities, a different composition strategy, such as Run-Time Composition, may be more suitable.

Run Time Composition

Micro frontend Runtime Composition is the process of dynamically combining and integrating individual micro frontends to create a unified user interface during the execution of the application via client’s browser.

Here are key aspects and characteristics of Runtime Composition:

1. Dynamic Loading: Micro frontends are loaded and integrated into the application dynamically as needed, typically in response to user interactions such as navigating to a specific page or requesting additional functionality.

2. Flexibility: Runtime composition provides a high degree of flexibility as components are not pre-determined during the build process. This flexibility is beneficial for scenarios where the composition structure needs to adapt to user behavior or changing requirements.

3. Granular Updates: Individual micro frontends can be updated independently at runtime without affecting the entire application. This allows for more granular updates and reduces the need for full application reloads.

4. Lazy Loading: Components are loaded lazily, meaning that only the necessary parts of the application are fetched and executed when required. This can contribute to faster initial page loads and improved performance.

5. Micro Frontend Autonomy: Each micro frontend operates independently, and its behavior is determined during runtime. This autonomy allows development teams to work on their micro frontend without extensive coordination with other teams during the development phase.

Runtime Composition is particularly suitable for scenarios where the application’s structure needs to be adaptive, and the loading of components can be determined on-the-fly based on user interactions or other runtime conditions. It offers flexibility and allows for more dynamic, user-driven experiences in micro frontend architectures. Several tools and frameworks are available to facilitate runtime composition in micro frontend architectures. These tools help manage the dynamic loading, integration, and communication between independently developed micro frontends during runtime. Here are some popular runtime composition tools:

• Single-spa: JavaScript framework for building micro frontend architectures. It provides a set of utilities for composing and loading micro frontends at runtime. Single-spa supports various frameworks such as React, Angular, and Vue.

• SystemJS: A dynamic module loader that supports loading modules at runtime. It can be used for runtime composition in micro frontend architectures, allowing components to be loaded on demand.

• Webpack Module Federation: Webpack introduced the concept of “Module Federation” as part of its features. It allows developers to dynamically load and share JavaScript modules between applications at runtime, making it suitable for micro frontend architectures.

Micro Frontends are microservices running in the client browser, The idea is to build feature-rich and powerful browser applications as compositions of features owned by independent teams. Fusionize orchestrate Micro Frontends (MFE), utilizing Single-spa to manage MFE lifecycle and routing, and SystemJS for loading and overseeing distributions and dependencies at runtime.

Bottom–up and top–down design

Bottom-Up Design:

In bottom-up design, the system is constructed from the bottom, or most basic, components up to the higher-level components and ultimately the complete system. The process starts with the development of individual modules or components, often focusing on low-level functionality. Once these smaller components are created and tested, they are gradually combined to form larger subsystems, and this process continues until the entire system is built.

Benefits include:

• Incremental Development: It follows an incremental development approach, building and testing small components before integrating them into larger structures.

• Modularity: The system is broken down into modular, manageable components that can be developed and tested independently.

• Early Testing: Components can be tested early in the development process, allowing for early detection and correction of issues.

• Focused on Implementation Details: Design starts with a focus on implementation details, addressing specific functionalities and features.

• Flexibility: It offers flexibility in changing or substituting individual components without affecting the entire system.

Top-Down Design:

In top-down design, the system is designed and constructed from the top, or highest level, down to the lower-level components. The process begins by defining the overall structure and functionality of the system at a high level. Then, the high-level components are gradually refined and broken down into more detailed and specific components. This decomposition continues until the entire system is fully defined and implemented.

Benefits include:

• High-Level Overview: It starts with a high-level, abstract view of the system, defining its overall architecture, functionalities, and interactions.

• Stepwise Refinement: The high-level components are successively refined into more detailed and specific components in a stepwise manner.

• Early Focus on System Architecture: Emphasis is placed on defining the overall system architecture before delving into the specifics of individual components.

• Guided by Requirements: The design process is guided by the system requirements, ensuring that the final system meets the specified criteria.

• Clear Interface Definitions: Well-defined interfaces between components are established early in the design process, allowing different teams to work on different parts concurrently.

Comparison:

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• Development Flow:
  • Bottom-Up: Starts with the smallest components and gradually builds up to the complete system.
  • Top-Down: Begins with an overarching view and progressively breaks down the system into smaller components.

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• Testing:
  • Bottom-Up: Enables early testing of individual components.
  • Top-Down: Early focus on high-level design may delay testing until lower-level components are developed.

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• Flexibility:
  • Bottom-Up: Offers flexibility in substituting or modifying individual components.
  • Top-Down: Provides a clear architecture but may have less flexibility in terms of altering the overall system structure.

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• Efficiency:
  • Bottom-Up: Can lead to quicker development of basic functionalities.
  • Top-Down: Ensures that the system architecture aligns with overall goals and requirements.

Real-world Scenario for a book store website

• Top-Down: Starts with top level view of website layout, considering different sections like, book search, suggestions ,reviews, QA, carts and purchase history.
• Bottom-Up: Starts with one or two critical section’s component, like, book search and shopping cart without considering final layout and flow and will break it down to components like “Add to cart” button and list view of books.

In practice, a hybrid approach is employed, a blend of top-down and bottom-up methods that tends to favor one over the other. However, the Agile and Lean software development methodology aligns more with the bottom-up approach. For instance, the functionality of book reviews and suggestions becomes effective when a substantial number of users have started using the website. Therefore, in the initial stages, it might not be ideal to prioritize and focus on these sections.

Micro Frontends are an ideal approach for bottom-up solutions, fusionize library includes components such as mountable and mount-place To design and develop different sections without worrying about the overall layout and structure, create flexible components that can be easily moved around without requiring extensive refactoring.

Flat vs Hierarchical modules

The terms “flat” and “hierarchical modules” refer to different ways of organizing and structuring elements within a system. Here’s an overview of each:

Flat Modules: In a flat component structure, elements or modules exist on the same level without a clear hierarchy. Each component is relatively independent and can interact directly with others.

• Components exist on the same level.
• Looser coupling between components.
• Each component is relatively independent.
• Simplifies certain interactions.
• Can be more adaptable and flexible.

Hierarchical Modules: In a hierarchical component structure, modules are organized in a clear hierarchy, with parent-child relationships. Each component may have sub-components or child elements that contribute to its overall functionality.

• Components organized in a hierarchy.
• Clear parent-child relationships.
• Tighter coupling between components within the hierarchy.
• Well-defined roles for each level.
• May provide a more structured and organized approach.

Comparison:

Critteria	Flat Components	Hierarchical Components
Independence	Components are relatively independent	Components may depend on or interact with each other in a structured hierarchy
Complexity	Simplicity and adaptability	More structured and organized, potentially expensieve to maintainace for complex systems
Flexibility	Greater flexibility but less structured	Provides a clear structure but may be less flexible in some cases
Communication	Looser coupling, potentially simpler interactions	Components communicate within a defined hierarchy

“Top-down” and “bottom-up” designs shape how modules and components are structured. Although a flat structure may not be ideal for a company organization chart, considering bottom-up approach and flat module structure, will simplifies UI development

fusionize Orchestrate Micro frontends (MFE) within a flat structure devoid of hierarchy, fostering simplicity, flexibility, and a loosely coupled MFE architecture.