Micro Frontends: Advantages, Best Practices, How to Build

If you're reading this article, you've encountered the term 'Micro Frontend' at some point. Perhaps you had to deal with it on a small scale or overheard someone talking about it. Whichever the case may be, we’re sure you're baffled by the term.

We wrote this article to help those looking to step into Micro Frontends. In short, Micro Frontends will drastically improve your frontend development process. By following this guide, you'll learn how to build scalable frontends, leading to an easier time when developing future projects.

We know this might sound a bit unconventional initially, but once you've completed the entire guide and implemented some of these techniques on one or two projects, we’re sure you'll thank us for writing this.

Micro frontends are revolutionizing web development. Instead of building a monolithic front-end application, you split it into small, independent applications with their own technology stacks and deployment pipelines.

This approach has significant benefits, including autonomous teams, focused development, flexible tech choices, and fast innovation. However, it also introduces complexity, makes reusing components harder, complicates testing, and requires careful management of routing and dependencies between frontends.

Implementing micro frontends typically involves module federation, web components, iframes, or server-side composition. It relies on robust tooling and processes like component libraries, CI/CD pipelines, monitoring, debugging tools, and style guides.

Micro frontends allow frontend developers to build and deploy faster but also introduce complexity and new challenges. To reap the benefits of micro frontends without suffering the drawbacks, it’s essential to understand how they work and why they are helpful in the first place.

So you've heard about the micro frontend trend and want to try it out. Maybe you're just curious or convinced that it will reduce your application's load time by a good few seconds.

Whatever your reason, I'm here to tell you that micro frontends are not just a solution to slow websites. They can also make development faster, easier, and more enjoyable.

Each component can be considered a micro frontend and consists of one or more pages. These pages could be static or dynamic, but it doesn’t matter — what matters is that every page has its URL to function independently.

Micro frontends are a relatively new concept. They're essentially small, self-contained applications designed to run on the user's browser. These micro frontends can be used to create a more personalized and engaging experience for your users.

Micro-frontend architecture is a new approach to frontend development that aims to solve some problems when building large-scale web applications. It's a practical approach that can be implemented as an alternative to traditional monolithic architectures.

The idea suggests splitting front-end development into smaller microservices, which developers can deploy independently. Each microservice is responsible for a specific feature or functionality.

When we talk about splitting our components, we usually talk about splitting them into smaller ones. But in reality, the term "micro" should be interpreted differently from one person to another.

Some may consider a component with more than 100 lines of code as not being "micro." Others might say that anything less than 200 lines of code is considered micro.

There's no actual definition for what makes a component "micro," so you'll have to figure out what works best for your development team by experimenting over time with different approaches.

Micro frontends are built with modern JavaScript frameworks like Vue.js or React and are rendered on the client side by the user’s browser. They often use preprocessors like Babel to convert ES6/ES7 code into more familiar JavaScript syntaxes like ES5 and ES6 so they can run in browsers that don’t natively support newer JavaScript features.

Micro frontends are often used in conjunction with server-side rendering (SSR). SSR is the process of rendering a page on both the server and client side, which means once a user requests your application for the first time, they'll see a fully rendered version.

Once an application has been requested once, subsequent requests will only need to run through any JavaScript that's changed since their last visit—which can drastically improve performance.

The architecture consists of the following components:

Small, independent frontends

This is the most important part of your architecture. The frontends should be small, independent components that can be used to build any application. They should have no dependencies on other components and be able to run independently (if needed).

Own tech stack

Each micro front end should be able to use a different technology stack. For example, one component could use React and Redux while another uses Vue and Apollo. You can even have frontends built with serverless functions or other non-traditional approaches.

Own deployment

Each front end can be deployed independently and even on different servers. One component could be deployed to AWS and another on Azure or Google Cloud. How you deploy them should be left up to each team so they can choose the right tool for each job.

Communication between frontends

To have a flexible system that can adapt to change, you must ensure that your front ends predictably communicate. One of the best ways to do this is using an API gateway or microservice. This allows each team to create their API, which others can use without access to any other application part.

In a monolithic architecture, everything happens in one big application. You have one code base that runs on one server and serves all pages for your users. It is not easy to upgrade or fix something without affecting other parts of your system. In addition, if one component fails, it affects all users/pages served by that component — which can lead to downtime!

In contrast, in a microservices architecture, everything is broken down into more minor services. These services communicate with each other using APIs or messaging queues to coordinate their actions. This allows you to upgrade, fix, and manage individual components without affecting the whole system.

You can also deploy these services independently, which makes scaling easier because there are fewer moving parts.

Similarly, micro frontends allow you to build the frontend modularly, making it easier to scale. You can also break down the application into multiple microservices that communicate with each other using APIs or messaging queues.

This allows you to upgrade, fix, and manage individual components without affecting the whole system.

As a result, micro frontends have better performance and scalability than traditional monolithic frontend applications.

Scaling the front end has been a top priority for many companies in recent years. With the advent of single-page applications (SPAs), users can now experience a seamless, fast, and highly efficient user experience.

In addition to this, there is also a clear separation between the business logic and presentation layer. This allows for easier maintenance and refactoring of both parts.

In addition, micro frontends help us scale our application as we build out new features or change existing ones. This happens because each component or page is isolated from other components and pages.

The developer can focus on his or her own responsibilities without worrying about any other part of the application. This makes it easier for developers to collaborate and maintain their codebase over time.

Situations where micro frontends prove to be highly effective:

Isolated teams

Micro frontends help to isolate teams and allow them to work on their components independently. This is useful when multiple teams have different skill sets or are working on different features that don’t necessarily need to interact with each other.

For instance, in a large application with many different development teams working together on the same project, micro frontends allow each team to focus on its responsibilities without worrying about any other part of the application. This makes it easier for developers to collaborate and maintain their codebase over time.

Micro frontends also allow teams to work on different components or features simultaneously. This gives developers more flexibility when planning their release cycles and allows them to ship new features faster by only deploying the ones that have been completed.

Focused development

A component or page is the smallest development unit in a micro frontend architecture. A component should be able to do one thing and do it well. This makes it easier for developers to focus on their responsibilities without worrying about anything else.

This also makes it easier for developers to collaborate and maintain their codebase over time. Micro frontends are good for large applications focusing on one feature at a time. This can be especially useful when developing new features or making significant changes to existing ones.

Flexible tech choices

A micro frontend architecture is flexible and allows you to use any technology you want. You can choose from a variety of frameworks, libraries, and tools. This allows developers to implement different features differently depending on what works best for them and their applications.

This flexibility also allows developers to experiment with new technologies, which can result in better applications. They don’t need to worry about breaking anything since any changes will be isolated from the rest of the application.

Resilient systems

Micro frontends are resilient, which means they’re more likely to survive in the long term. This is because they’re built on a solid architecture that won’t succumb to changes in technology or business requirements. Micro frontends also allow you to make changes without affecting other parts of your application.

It only affects the micro front end if you need to add a new feature or change. Since those changes are isolated, you don’t have to worry about breaking other parts of your micro frontend application.

Fast innovation

Micro frontends give you the ability to innovate faster. This is because they allow you to experiment with different technologies without worrying about breaking your existing codebase.

You can update and replace modules more easily, making it easier for developers to get their hands on new tools as quickly as possible.

Micro frontends are also more flexible. If you have a lot of different teams working on different parts of your application, they can work on their micro frontend without impacting the rest of your codebase. This lets them iterate faster and more efficiently than ever before.

Easier to maintain, test, and reuse code

Micro frontends allow you to split your frontend code into smaller components, which makes it easier for developers to maintain, test, and reuse code. This is because each micro frontend only contains the logic necessary to render a single view of your application. You can also easily share common logic across multiple micro fronts using an API server or shared database.

Less code means less room for bugs and errors. If you split a large application into micro frontends, you’d have many separate pieces of code with fewer lines of code than the original. This reduces the scope for error when developing new features or fixing bugs because there are fewer lines of code in each micro frontend to read through and test.

As you can see, there are many advantages to using a micro-frontend approach. However, there are some challenges as well. The most important ones that we can find are:

Increased complexity

A micro-frontend approach can add complexity to your application by introducing more moving parts.

For example, if you are using a micro frontend for each page of your application, then you have to manage multiple instances of your application on different ports. This will require additional work when it comes time for debugging or maintenance.

Testing difficulties

Testing can be difficult because of the increased complexity. As you saw above, it is important to test each application component individually. However, when you are using multiple instances of an application on different ports, this becomes more challenging.

You must write tests that run on all instances simultaneously and ensure they pass before deploying changes.

Routing

Difficulties The most significant difficulty you will run into when using multiple instances of an application on the same host is routing. Routing is determining where a request should be sent based on its URL. In other words, it tells your web server what application to run based on the request’s pathname.

If you have multiple micro apps running on the same host, you must configure routing to work correctly for each application. You can do this by configuring your webserver to use a different port for each application and setting up routing rules in your operating system’s network stack.

Managing dependencies

It would help if you managed dependencies between multiple instances of an application on the same host. This includes ensuring they use the same version of dependent libraries and that their configuration files are compatible.

If a dependency has changed since it was installed on one instance and not another, it may cause problems for your application when transitioning between running on two machines or more at once.

With micro-frontends, you can build small, focused applications that are easier to maintain and extend. These applications are also more secure because they have less surface area than a monolithic app.

Besides security, another advantage of using micro-frontends is that each part of your application can be upgraded independently of other parts. This makes implementing features like A/B testing or rolling out new versions of your product easier while minimizing downtime and bugs.

It’s worth noting that micro-frontends are not a new concept. Most modern websites are built using this approach. Each page on your website is its component, which makes it easier to maintain and extend.

Shared component libraries

You can use shared component libraries to reduce the code you need to write, improve consistency across your application, and reduce maintenance costs. They can also help with performance by reducing the HTTP requests required for each page load.

A shared component library is a set of web application UI components shared across multiple micro-frontends. These components can be written in any modern programming language, but it’s best to use one that’s easy to learn and familiar to the people working on your project.

For example, Vue is a popular JavaScript framework for building web applications. It allows you to create reusable components used in other projects or by other developers on your team.

It’s important to note that you should build micro-frontends with a shared component library in mind. This means the components are designed to be used as standalone pieces of code, which you can then incorporate into your project. For example, if your team has written a set of reusable Vue components, you could use them in any project using Vue.

Testing micro frontends

Testing is another important part of micro frontend development. Micro-frontends are small and modular, so you will likely have many components to test. Testing these components individually is possible but time-consuming and difficult to manage when the number of tests increases.

A better solution would be to create a shared component library with tests built into it—this ensures that any changes made to your components won’t break any existing code in your application.

• Unit tests are used to test individual components or small groups of components.
• Integration tests are similar to unit tests but cover larger areas of your application.
• End-to-end (E2E) testing can be useful for validating that your entire application works as expected.

Testing is important because it helps ensure your application works as expected. It also allows you to detect bugs before they’re deployed and can help write higher-quality code.

Implementing Micro Frontends can be achieved using various techniques. Here are four commonly used approaches:

1. Module federation

Module federation is a technique that allows you to split your application into different components or modules, which can be reused across projects. This approach allows you to create independent components that are easier to maintain and update. Some of the benefits of using this technique include:

• Being able to easily share code between projects.
• The ability to use community-driven open-source libraries where possible instead of maintaining your own custom solutions.

2. Web components

Web components are a collection of standards-based technologies that allow you to create your own custom HTML elements. These elements can be used just like any other native HTML tag and allow you to encapsulate complex functionality into reusable building blocks.

Some of the benefits of using web components include:

• They provide a way to encapsulate complex functionality into reusable building blocks.
• They make it easier to create and maintain large applications by allowing you to break them down into smaller, more manageable pieces.

3. iframes

Iframes are a way of embedding content into your website. This can be useful when you want to display third-party content on your site, such as embedded videos from YouTube or Vimeo. This approach is also useful for creating “widgets” that can be reused throughout your application in various places.

The iframe can be used in conjunction with JavaScript to allow you to dynamically change the content that is displayed within it.

4. Server-side composition

In this approach, the composition of micro frontends happens on the server side. The server takes care of aggregating the different micro frontend modules and delivering a unified HTML response to the client side. This approach allows for dynamic composition based on the user's request and can help improve initial page load performance.

Server-side composition also makes it easier to enforce a consistent layout across your application. You can use a templating framework such as Handlebars or Nunjucks to create a layout template that all micro frontends share, and then use server-side logic to inject data into the HTML at render time.

When implementing Micro Frontends, several tools and processes can enhance the development and maintenance of the architecture. Here are five important aspects to consider:

• Component Library: Creating a component library can help improve the consistency of your application. Components should be designed to work together and adhere to common guidelines. This makes it easier for developers to create new components and helps ensure that every component is semantically correct and follows best practices when using HTML, CSS, and JavaScript. The library can create new components and provide existing ones with a solid foundation. Each component should include documentation that explains how it works and what it does. This will help developers understand how each component fits into the greater whole.
• CI/CD pipelines: A CI/CD pipeline is a tool that automates the process of building, testing, and deploying your code. The purpose of a CI/CD pipeline is to ensure that every change made to the project is tested before it’s deployed on production. This makes it easy for developers to work on their branches without worrying about breaking anything because they can merge their changes when ready to release.
• Monitoring: Monitoring is a crucial part of any project, but it’s especially important in the case of web apps. You need to see how your application performs under different conditions and identify performance bottlenecks before they affect end users. Monitoring can help you reduce users' time to access the application by quickly identifying and fixing problems so nobody notices anything goes wrong.
• Debugging: Debugging is one of the most important aspects of software development. The ability to debug code quickly and efficiently can make or break a project, but it’s especially critical for web applications because there are so many different layers at work. You need to easily find problems in your code without spending days tracking down bugs that may not even exist anywhere other than your imagination.
• Style guides: Establishing a style guide for your team can help you reduce the time spent arguing over coding styles and formatting. By having a single reference point, everyone on the team knows exactly how things should be done. This also allows new developers to jump right into working on your project without spending precious time learning how things are done in your project.A good style guide should cover everything from how to format your code to how to write comments. It should also include a list of common gotchas and potential pitfalls so that new developers can avoid making mistakes that may take you hours to fix.

If you’re building a micro frontend, some best practices can help you get the most out of your project.

• The micro frontend architecture is easy to understand but can be difficult to implement. This is especially true when you have a large team of developers who are used to working on traditional monolithic applications.
• When building micro frontends, all developers must have access to the same set of tools and libraries to share code between projects easily.
• The most important thing to remember when building micro frontends is that your applications should be as modular as possible. You want to create self-contained components that can be reused without any modifications. This will help you avoid having to rewrite code across multiple projects, saving you time in the long run.
• The micro frontend approach is a great way to build reusable and modular code. It allows you to create smaller and more manageable applications, making it easier for developers to maintain and fix if bugs occur. It would help if you also considered using this approach when building applications that need to be updated frequently, as it will make it easier for your team to iterate on new features without breaking existing functionality.
• The micro frontend approach can help you build applications faster, allowing you to iterate on new features without having to rewrite large amounts of code. It also makes it easier for developers to maintain and update existing applications, saving you time in the long run.
• The micro frontend approach is best used when you need to iterate on new features quickly or when you have many teams working on the application. It can also reduce bugs in your codebase by keeping it more organized and allowing developers to isolate changes that cause problems easily.
• Other scenarios where micro frontends are best to use are: 1. When building applications that need to be updated frequently. 2. When you want to separate business logic from presentation logic. and 3. When making changes to an application's front end requires too much effort or time.
• But it's not best to use micro frontends when your application is simple and has few features. If you're building a simple application, keeping all of your frontend code in one place is usually best.

Micro-frontends are a powerful tool for building better applications. They make it easier to maintain and extend your application so you can focus on what matters: creating great software.

As you have seen throughout this article, micro frontends are a new way of developing front-end interactivity. They offer significant advantages when compared to their monolithic counterparts. Chief among these advantages is that micro frontends are scalable.

As a component system grows and a project becomes more complex, efficiency is highest if each component is isolated and not entangled with other components that behave or look differently.

Well-built micro frontends allow for true modularity within an application's front end, avoiding the need for powerful CSS preprocessors or JavaScript frameworks. Micro frontends solve problems associated with larger projects using the same modular techniques modern web frameworks employ.

Overall, micro frontends are a big step forward in front-end development. They reduce code duplication and promote reusability, and they do so without sacrificing any of the same customizability that full-featured frameworks provide.

They could facilitate faster development and more rapid iteration as a team of developers rapidly prototypes different ideas without slowing down the main application. There is a lot to like about micro frontends; they could become the next big thing in frontend architecture.

With the strategic use of micro frontends, you can build websites that load content at lightning speed. If used correctly, you can help improve your website's overall user experience and make it more SEO-friendly. In other words, micro frontends are an excellent way to provide many visitors a better experience.