What are Micro Frontends?

Among the more widely accepted frameworks at the moment, there is a concept known to be a Micro Frontend. The technique extracts the ideas from microservice architecture in the backend portion and implements them in the front end by breaking down the irrelevant large frontend applications into more manageable self-sufficient components.

1. What are Micro Frontends?

Micro frontends are an architectural pattern that applies the concepts of microservices to the frontend development. Instead of building a single monolithic frontend application, a micro frontend architecture involves breaking the frontend into smaller, independently deployable and scalable units called micro frontends.

2. Fundamentals of Micro Frontends

At the core of Micro Frontends lie several fundamental principles:

• Single Responsibility:
  • Every micro frontend module should have a clear and separate duty, which can concentrate on a specific performance or a kind of function.
  • This principle does so by making the code inside the module more constructive and has a concise focus, which will offer better maintainability and extensibility.
• Loose Coupling:
  • Interaction between Micro Frontends needs to be through a well-defined interface such as separate smaller chunks to avoid huge dependencies and coupling between modules.
  • Loose coupling lets the modules be separated and evolve themselves quickly unlinking the whole system.
• High Cohesion:
  • Cohesion within a Micro Frontend architecture translates its meaning as a concept of decomposing related functionality to different modules.
  • High cohesion that is inherent in code increases code readability, maintainability, and code reusability.

3. When should you use Micro Frontends?

Micro frontends are a suitable architectural choice in various scenarios. Here are some situations where you should consider using micro frontends

• Large and Complex Applications: When building applications with intricate user interfaces and functionality, micro frontends allow you to divide the system into smaller, manageable parts. This facilitates easier development, maintenance, and scalability.
• Multiple Development Teams: If your project involves several development teams working on different parts of the frontend, micro frontends enable each team to work independently on their own micro frontend. This promotes autonomy, faster development cycles, and easier collaboration.
• Diverse Technology Stacks: In environments where different parts of the application require different technologies or frameworks, micro frontends allow you to integrate these technologies seamlessly. Each micro frontend can be developed using the technology stack that best suits its requirements, promoting flexibility and innovation.
• Scalability and Performance: Micro frontends offer scalability benefits by allowing you to scale individual components independently based on demand. This enables better resource allocation and performance optimization, especially in scenarios with fluctuating traffic or resource requirements.

4. Architectural Patterns of Micro Frontends

Several architectural patterns can be employed to implement Micro Frontends:

1. Single-SPA (Single Page Application):

In this pattern, the entire application is a single-page application (SPA) composed of multiple micro frontends.

• Each micro frontend represents a self-contained section of the application, and the routing logic dynamically loads and integrates these micro frontends into the SPA based on the requested URL.
• Single-SPA provides a unified approach to managing multiple micro frontends within a single application, allowing for seamless navigation and user experience.

2. Composition at the Edge:

In this pattern, composition of micro frontends occurs at the edge of the network (e.g., CDN or reverse proxy), rather than in the client’s browser.

• Edge servers dynamically assemble the user interface by fetching and combining micro frontends from various sources based on the requested URL or user context.
• Composition at the edge improves performance by reducing client-side processing and latency, as well as enhancing security by centralizing composition logic.

3. Client-Side Composition:

In this pattern, composition of micro frontends occurs on the client-side, typically in the browser.

• The client-side router or orchestrator dynamically fetches and integrates micro frontends into the user interface based on the requested URL or user interactions.
• Client-side composition offers flexibility and responsiveness, allowing for dynamic updates and interactions without requiring server-side processing.

4. Server-Side Includes (SSI):

In this pattern, the server dynamically includes or includes micro frontends into the server-rendered HTML response based on the requested URL or user context.

• Server-side includes (SSI) allow for efficient server-side composition of micro frontends, reducing client-side processing and improving performance.
• SSI can be implemented using server-side templating languages or edge computing platforms to assemble the user interface on the server before sending it to the client.

5. Communication between Micro Frontends

Solid interaction between Micro Frontends is a key that will help create a wholesome and consistent experience for users. Several techniques can be employed to facilitate communication:

• Custom Events:
  • Micro frontends can communicate with each other using custom events dispatched through the browser’s native event system (e.g., CustomEvent in JavaScript).
  • One micro frontend can dispatch an event with relevant data, and other micro frontends can listen for and respond to these events accordingly.
  • Custom events provide a lightweight and flexible way to enable communication between micro frontends without tight coupling.
• Shared State Management:
  • Micro frontends can share state by storing it in a shared location, such as a global state management solution or a centralized data store.
  • State management libraries like Redux, MobX, or Vuex can be used to manage shared state across multiple micro frontends.
  • By updating and subscribing to shared state, micro frontends can stay synchronized and maintain consistency across the application.
• API Gateway or Backend Services:
  • Micro frontends can communicate with backend services or API gateways to fetch data or trigger actions.
  • Backend services can act as intermediaries, handling requests from micro frontends and orchestrating interactions between them.
  • This approach allows micro frontends to remain independent while leveraging centralized services for communication.
• Message Bus or Pub/Sub Systems:
  • Micro frontends can communicate through a message bus or publish-subscribe (pub/sub) system.
  • Each micro frontend can publish messages to specific topics, and other micro frontends can subscribe to these topics to receive relevant messages.
  • Message bus or pub/sub systems enable asynchronous communication between micro frontends and support decoupled and scalable architectures.

The mode of communication on the other hand depends on the factors which may include the nature of interactions that are desirable, user performance, and the development being preferred.

6. Integration of Micro Frontends with Backend Services

Micro frontends, which represent modular and independent frontend components, often need to communicate with backend services to fetch data, perform actions, and synchronize state. Below is an explanation of how micro frontends can be integrated with backend services:

• API Contracts:
  • Clearly define interfaces between micro frontends and backends, including endpoints and data formats.
  • Ensure standardized communication protocols for consistency and interoperability.
• Backend For Frontend (BFF) Pattern:
  • Develop specialized backend services for each micro frontend to handle specific frontend needs.
  • Abstract complexity and provide tailored interfaces optimized for frontend requirements.
• API Gateways:
  • Serve as centralized entry points for micro frontends to access backend services.
  • Simplify integration by aggregating data from multiple backends and providing unified interfaces.
• Authentication and Authorization:
  • Implement secure authentication mechanisms like OAuth or JWT for user verification.
  • Enforce access controls based on user roles and permissions to protect sensitive resources.
• Data Fetching Strategies:
  • Optimize data retrieval methods to minimize latency and enhance performance.
  • Use techniques such as caching and prefetching to reduce round trips and improve user experience.
• Error Handling and Resilience:
  • Develop robust error handling mechanisms to gracefully manage failures and disruptions.
  • Employ strategies like retries and circuit breakers to mitigate issues and maintain system reliability.

7. Development Approaches for Micro Frontends

Teams can adopt various development approaches when working with Micro Frontends, depending on organizational structure, project requirements, and team dynamics:

• Feature Teams:
  • The feature team is a cross-functional team comprising of members who work together on the development of the end-to-end features along with the user stories.
  • The architecture will be following the Feature Team structure whereby a feature team will manage one or more Micro Frontend modules so as to provide seamless user experience across different feature components
• Component Teams:
  • Team members dedicate time to coming up with classes written in HTML/eCSS and that can be reused by most Micro Frontends.
  • Component teams work to eliminate code replication, ensure adherence to a common design language, and create well-organized and up-to-date projects through their development of standardized UI components and design patterns.
• Cross-Functional Teams:
  • Teams are cross-functional and support them is provided by the members who have their gathered and comprehensive skills and expertise as developers of the front-end, backend, designers and testers.

Rapid iterations and frequent releases are enabled by continuous integration and delivery (CI/CD) pipelines that condense development workflows and reduce human participation, with proven results in the production of defect-free solutions. The CI/CD pipelines greatly simplify the build, test, and deployment procedures eliminating significant manual overhead and leading to bigger efficiencies.

8. Scalability and Performance Considerations for Micro Frontends

Below are the scalability and Performance Considerations for Micro Frontends:

• Scalability:
  • Design micro frontends to scale horizontally by adding more instances to handle increasing load.
  • Use efficient data fetching strategies and caching mechanisms to minimize server load and improve scalability.
  • Implement distributed architectures that can dynamically allocate resources and balance traffic across micro frontends.
• Performance Considerations:
  • Optimize client-side rendering and minimize DOM manipulation to improve frontend performance.
  • Utilize lazy loading and code splitting techniques to reduce initial page load times.
  • Implement efficient data fetching mechanisms and cache frequently accessed data to reduce latency and enhance responsiveness

9. Testing Strategies for Micro Frontends

Thorough testing needs to be a compulsory condition to reach a high level of reliability, solidity and strongness of Micro Frontends.Testing strategies may include:

• Unit Tests: The unit tests are utilized for the validation of these modules or components which individually verifies that they behave as it should and meets the expectation of the requirements between the modules.
• Integration Tests: Integration testing determines whether or not there are any conflicts between the different micro frontend modules or between micro frontends and backend services, but there are no issues with their ability to work together properly.
• End-to-End Tests: End to end tests act as user interface mimics and establish the appropriate functionality across all the components of the application, thus confirming proper end to end behavior of the entire application.
• Contract Tests: In order to avoid a situation where Micro Frontends aren’t communicating with the backend services in a uniform way, i.e. according to the expected contracts and standards, these tests should be considered.

Automated unit tests with tools like Jest, Cypress, and Puppeteer can help to carry out testing at multiple levels and this will accelerate feedback cycles while ensuring the quality of Micro Frontends is at highest.

10. Security Best Practices for Micro Frontends

Security is no less important as we are getting into saving Micro Frontends, regardless of the fact that we are in a field of mobile and/or isolated apps and environments. Several security best practices should be followed:

• Isolation:
  • Ensure strong isolation between micro frontends to prevent one compromised component from affecting others.
  • Use web sandboxing techniques like iframes or web components to encapsulate each micro frontend.
• Authentication and Authorization:
  • Implement secure authentication mechanisms to verify user identities before accessing sensitive data or functionalities.
  • Enforce proper authorization checks to ensure that users only have access to resources they are authorized to use.
• Secure Communication:
  • Encrypt data transmission between micro frontends and backend services using HTTPS to prevent eavesdropping and data tampering.
  • Employ techniques like JSON Web Tokens (JWT) or OAuth for secure authentication and authorization between micro frontends and backend APIs.
• Input Validation and Sanitization:
  • Validate and sanitize all user inputs to prevent injection attacks like XSS (Cross-Site Scripting) and SQL injection.
  • Use libraries and frameworks with built-in input validation features to ensure data integrity and mitigate security risks.

11. Deployment and Continuous Delivery

An along with the input technology , delivery pipelines are fundamental for redeploying changes in production with success and at high speed. Key considerations include:

• Containerization: Containers like Docker, which are containerization technologies, allow to package and distribute micro frontends together with their dependencies to deployment environments in a standardized way.
• Orchestration: Orchestration platforms like Kubernetes usually automate the setup and management of Micro Frontends on behalf of the platform with features of load balancing, service discovery and self-healing.
• Continuous Integration (CI): A CI pipelines have the ability to automate the environment for design, testing and verification of Micro Frontends, in order to guarantee that they comply with all the quality standards for release to the marketplace.
• Continuous Deployment (CD): CD pipes is another name for automatic deployment of the changes done to production environments, which reduces the volume of human labour and makes the delivery processes faster and more advanced.

Using DevOps and CD practices allows organizations to reduce deployment time, improve reliability and create contingency plans to mitigate deployment risks while enhancing their speed and agility.

12. Monitoring and Observability

Constant monitoring and observability for problem detection and resolution are a must-have for Micro Frontend applications to function correctly.Key practices include:

• Metrics Collection: Measuring metrics on the user experience, such as performance, availability, and problems faced by the user helps to identify the causes for the bottlenecks, anomalies, and trends over time.
• Distributed Tracing: Distributed tracing ensures complete visibility on spans that they cover as they travel through different Micro Frontend modules, as well as backend services, thus making root cause analysis and troubleshooting relatively easier.
• Logging: Logging supplies information on logging not only on the events, errors, and interactions within Micro Frontends, includes incident investigation as well.
• Alerting: The mechanisms of the alerting notify the different IEs of the system when any issue which is categorized as critical occurs or an anomaly is shown in Micro Frontend applications, permitting the players to respond immediately and minimizing any possible risk.

Companies that invest in development and utilizing monitoring tools and practices will have the opportunity to preemptively steer and tailor the operation of Micro-Frontend solutions.

13. Challenges and Solutions

Below are the challenges of Micro Frontends and their solutions:

1. Isolation:

Ensuring strong isolation between micro frontends is crucial to prevent interference and conflicts. Solutions include utilizing techniques like web components or iframes to encapsulate each micro frontend and establish clear boundaries and contracts between them.

2. Communication:

Coordinating communication between micro frontends without tight coupling is essential. Solutions involve adopting event-driven architectures or publish-subscribe patterns for communication and implementing shared services or APIs to exchange data in a decoupled manner.

3. State Management:

Managing shared state and ensuring consistency across micro frontends can be challenging. Solutions include using centralized state management solutions like Redux or MobX and implementing event sourcing or distributed data stores to propagate state changes.

4. Performance:

Optimizing performance, especially in scenarios involving multiple micro frontends, is important. Solutions involve optimizing code splitting and lazy loading, implementing caching mechanisms, and prefetching strategies to reduce latency and improve responsiveness.

14. Case studies of Micro Frontends

Micro Frontends find applications across various domains and industries, including:

1. Spotify

Spotify adopted a micro frontend architecture to manage its vast and complex user interface. They divided their application into smaller, manageable components, allowing teams to work independently on different parts of the UI.

• Each team at Spotify is responsible for a specific micro frontend, enabling them to iterate quickly and deploy changes without impacting other parts of the application.
• Spotify’s micro frontend architecture has helped them improve development velocity, scalability, and maintainability of their application.

2. IKEA

IKEA revamped its online shopping experience using micro frontends to provide a more personalized and responsive user interface.

• By breaking down their monolithic frontend into smaller, reusable components, IKEA’s development teams can iterate more efficiently and deliver new features faster.
• IKEA’s micro frontend approach has allowed them to create a seamless omnichannel shopping experience, enabling customers to browse and purchase products across various devices and platforms.