Vue 3 Migration Case Study: Best Practices, Challenges, and Benefits

For any business using Vue.js as the foundation of its web applications, upgrading from Vue 2 to Vue 3 is a move that can significantly enhance your applications’ efficiency and productivity. Here’s why businesses and Vue.js consultants recommend making the move:

Vue 3’s Performance Upgrades: Speed and Efficiency

One of the standout benefits of Vue 3 migration is its improved performance. With an overhauled rendering engine and enhanced optimization techniques, Vue 3 ensures faster rendering speeds and better runtime performance. These improvements are particularly impactful for applications with complex UIs or large-scale user interactions, enabling smoother user experiences with less overhead.

Composition API Improvements for Better Code Organization

Vue 3 introduces the Composition API, a powerful new approach to writing and organizing component logic. Unlike the Options API in Vue 2, the Composition API allows developers to group related logic, making codebases easier to read, maintain, and scale. This feature is especially valuable for teams working on large applications or developers who want to share reusable logic across multiple components.

Enhanced TypeScript Support

As TypeScript adoption continues to grow in modern web development, Vue 3’s improved TypeScript integration is a game-changer. The framework was rewritten in TypeScript, leading to better type inference, cleaner typings, and a more seamless developer experience for those building type-safe applications. For businesses looking to move Vue2 to Vue3, the improved TypeScript support simplifies workflows and improves developer productivity.

Smaller Bundle Sizes and Enhanced Reactivity

Vue 3's modular architecture enables smaller bundle sizes, which is a direct win for performance optimization, especially in environments where load times are critical. Additionally, Vue 3 introduces a revamped reactivity system based on proxies, offering a more intuitive and efficient way to handle reactive states. This leads to fewer pitfalls, better debugging, and a smoother development experience.

Migrating to Vue 3 isn’t just about adopting new features; it’s about aligning your technology with the demands of modern web development to secure a competitive edge. Here’s how:

Scalability: As your applications grow in size and complexity, the tools introduced in Vue 3—like the Composition API and better TypeScript support—help developers maintain a scalable and clean codebase, reducing technical debt over time.

Maintainability: By embracing Vue 3’s improved code organization and tooling, teams can more easily onboard new developers, make changes to the codebase, and ensure long-term maintainability.

Competitive Advantage: Modernizing your application with Vue 3 allows you to deliver better performance and user experiences, keeping you ahead of competitors who are still relying on older, less efficient technologies.

Systems Engineering is a Danish company with which Monterail has been collaborating for the last four years. They started as a team of consultants developing and building system engineering projects. Still, over time, they created and then launched an application. We covered the development of this digital product, describing the whole case study of rewriting their React mobile application for improved user experience. 

With the framework’s sunset fast approaching, the decision to migrate Vue2 to Vue3 became a priority. The migration was an opportunity to address technical requirements and improve product quality and scalability. The team decided to start the migration in June to keep as much decision-making power as possible and have enough time before December 2023, when Vue 2 stopped being further developed and supported. With enough resources from the Monterail side, the team was ready to begin the migration process.

The Vue 2 to Vue 3 migration wasn’t without its challenges. Systems Engineering is a large digital product that heavily uses TypeScript. Luckily, supporting TypeScript is one of Vue 3's biggest advantages, so the team knew one aspect would be covered. 

One of the biggest technical challenges, but also an opportunity, was that once the application was migrated, it would have to use the existing Vue 2 ecosystem exclusively, with its libraries and components. Older Vue 2 features like portals with Vue 3’s built-in teleport component were replaced, which reduced the need for external dependencies and improved performance.

Vue 3 also includes a few updates to DOM render mechanics, which can easily enhance the performance of any application. The developers have also used Vuetify, an open-source UI Component Framework for Vue that was recently rewritten to be used with Vue 3. The dependencies were rewritten specifically for Vue 3 to ensure compatibility.

Thanks to that, the team could simplify the application maintenance process. With Vue 3, the team can also rely on Composition API, allowing us to reuse some parts of the code. We could also stop using portals and drop another dependency here. In Vue 3, there’s a native teleport component, and that’s very fitting as the Systems Engineering app uses a lot of portals. With the teleport component being used, the team no longer needs to download additional packages, which generally makes bundles smaller. Our team leveraged the Vue 3 migration best practices to simplify code reuse.

For the team at Systems Engineering, the migration from Vue 2 to Vue 3 wasn’t just a technical update—it was an opportunity to elevate their entire application to new heights of quality, performance, and maintainability. The process allowed them to take a step back, evaluate their existing codebase, and make meaningful improvements that translated directly into business value. Here's how Vue 3’s technical differences led to tangible benefits for their organization and product.

The migration process gave the team a rare opportunity to review every aspect of the application's front end thoroughly. Often, in a product's lifecycle, developers are focused on delivering features under tight deadlines, which can lead to compromises in code quality or the accumulation of technical debt.

During the migration, the team used the opportunity to:

• Identify Inconsistencies: Address inconsistencies in their codebase, ensuring a more unified and predictable structure across components.

• Fix Long-Standing Bugs: Hunt and resolve smaller bugs and errors that may have been overlooked or deprioritized in day-to-day development.

• Refactor Legacy Code: Replace older, less efficient code patterns with modern approaches enabled by Vue 3, such as the Composition API and the new reactivity system.

One of the most immediate benefits of migrating to Vue 3 was the measurable improvement in product quality. By transitioning to a framework with better performance and adopting Vue 3 migration best practices, the team was able to deliver:

• Enhanced User Experiences: Vue 3’s smaller bundle sizes and optimized rendering engine improved the application’s performance, leading to faster load times and smoother interactions for end users. This directly impacted user satisfaction and retention.

• Future-Proof Features: Leveraging Vue 3’s advanced features, like the Composition API, allowed the team to introduce better-organized and more reusable code, setting the stage for easier feature additions and updates in the future.

By embracing Vue 3’s advanced capabilities, the team at Systems Engineering positioned their product to stay competitive in the rapidly changing tech landscape. Modernizing their front-end architecture brought several long-term business benefits:

• Scalability: The use of Vue 3's Composition API allowed for modular, scalable code that can grow alongside the product without becoming overly complex or unwieldy. This positions the application to handle increased demand or new functionality in the future with minimal effort.

• Developer Efficiency: Vue 3’s improved TypeScript support and modern syntax made development faster and more reliable, helping the team deliver updates more quickly and with greater confidence. This not only sped up feature development but also reduced costs associated with debugging and technical debt.

• Better Tooling and Ecosystem Integration: Vue 3’s alignment with modern web standards and its compatibility with cutting-edge tooling (e.g., Vite for faster builds) ensured that the team could take advantage of the latest technologies, improving both their workflows and the product itself.

The process was split into multiple steps, allowing the team to progress quickly. The list of the migration steps included:

• Codebase audit: Estimating the complexity of the product and planning;

• Vue 3 compat build: This mode helps us get rid of compilers and the build time errors;

• Dependencies update: To make sure that will work with Vue 3;

• Testing & QA: Done for the upgraded version of the app, followed by fixing any bugs that were found.

Thanks to a well-written migration guide prepared by the Vue team, the Monterail and Systems Engineering developers had no issues following the steps to complete the process. They laid the foundations of a more robust and better-performing system. The migration process started with one of the in-house developers preparing the transition outline.

The team wanted the migration to not interfere with current development. They achieved that by introducing the incremental migration process and creating two parallel versions of the app. One would be replaced by the other once the Vue 3 variant was complete and ready to be deployed and used.

The biggest challenge was investigating performance issues in a few components. This caused a shift in the team's approach to developing new components in general and handling changes in properties and computed values. The team also focused on testing as much as possible to ensure the new system worked efficiently and as planned. 

The best thing any organization can do is start the migration process as early as possible. While the Vue 3 ecosystem was still a work in progress at the time, the most important libraries were there, ready to be used, and so was the support for Vue 3. He also recommends being mindful and open to any changes to your existing technology stack that may influence how it will look in the future. 

The testing process is also important to ensure the quality and performance of business functionalities. The Systems Engineering app is undergoing a series of manual and automated tests to assess whether the team needs to take additional steps in the migration process. The key here was not rushing the whole transition but incrementally completing the phases.

Migrating from Vue 2 to Vue 3 is far more than a technical exercise—it’s a strategic opportunity to enhance your application, streamline development, and future-proof your product. From boosting performance with smaller bundle sizes and faster rendering to adopting modern development practices like the Composition API and improved TypeScript support, Vue 3 empowers teams to build more scalable, maintainable, and competitive solutions. 

As demonstrated by the Systems Engineering case study, approaching the migration process thoughtfully—with proper planning, thorough code reviews, and incremental updates—ensures a smooth transition and creates tangible business value. Whether preparing for your migration or considering Vue 3 for a new project, embracing this upgrade isn’t just about keeping up with technology—it’s about stepping ahead and building with the future in mind. Partnering with Vue.js consultants will help reduce risk and maintain application functionality.

How does the Vue 2 to Vue 3 migration process look in practice? Why does it matter so much? What are the lessons learned for the team? These were the questions that Harald Hersted, Systems Engineering Concept Specialist at Systems Engineering, and Mateusz Michałowski, who works as a Principal Frontend Engineer at Monterail, addressed in the latest Vue event we organized in October 2023. Here’s where you’ll find the recording from this live discussion: