Common Mistakes When Starting in Front-End Development: How to Avoid Them and Improve Your Code

Introduction

Starting in the world of front-end development is exciting, but it is also full of challenges. Making mistakes is part of the learning process and, although frustrating at first, each mistake brings an important lesson. Whether you work with React, Next.js, TypeScript, or more general approaches, learning from these challenges can quickly take you to a more advanced level.

In this article, I share some common mistakes I faced when I started, how I solved them, and what I learned from them. I hope they help you avoid stumbling over the same stones!

Common Mistakes in React

Making mistakes in React, Next.js, and TypeScript is inevitable… but each one brings an important lesson.

1. Poor state management in complex applications

When I started with React, I used useState to handle any type of data. This worked for small projects, but as my applications scaled, maintaining consistency between states became a nightmare. My components rendered more than necessary and the data became inconsistent.

Example:

A large form managed the state of each input independently with useState. This caused multiple unnecessary renders, slowing down the application.

Solution:

I learned to use tools like useReducer for complex local states and libraries like RTK Query to efficiently handle asynchronous data. This organization reduced renders and made scalability easier.

Lesson:

Not all applications need advanced solutions, but for more complex projects, planning state management from the beginning is crucial.

2. Incorrect use of rendering methods in Next.js

Next.js greatly simplifies server-side rendering (SSR), but at first, I didn’t fully understand when to use getStaticProps, getServerSideProps, or getStaticPaths. This led to less efficient applications and unnecessarily long load times.

Example:

I implemented getServerSideProps on pages that didn’t require constant dynamic updates, wasting resources.

Solution:

• I used getStaticProps for static pages like blogs or product catalogs.
• I implemented ISR (Incremental Static Regeneration) for pages with dynamic data that didn’t need real-time updates.
• I reserved getServerSideProps for pages where data freshness is critical, such as dashboards.

Lesson:

Understanding how and when to use rendering methods in Next.js can improve performance and user experience.

3. Ignoring the power of TypeScript

At the beginning, I used TypeScript in a basic way, with generic types like any or unknown, without taking full advantage of its potential. This allowed silent errors that appeared in production.

Example:

I defined a state with any, allowing unexpected values that broke the component:

Solution:

• I explicitly typed data structures from the start:

• I used utilities like React.FC and AxiosResponse to type components and asynchronous functions.

Lesson: TypeScript not only helps prevent errors but also improves team collaboration by making the code easier to understand.

‍4. Not optimizing images in Next.js

‍In an e-commerce project, I forgot to use the next/image component, which resulted in long load times, especially on mobile devices.
‍
‍Example: I uploaded images directly to the public directory without compressing or resizing them.

Solution:

• I implemented next/image for automatic optimization, modern formats like WebP, and lazy loading.
• I configured a CDN to deliver images faster.

Lesson:
‍Optimizing images and resources is essential to improve user experience, especially in projects with high visual content.

‍5. Errors in dynamic routes

When working with dynamic routes and getStaticPaths, I didn’t properly validate data, which caused 404 errors in production.

Example:

I forgot to handle cases of non-existent IDs, leaving users with a broken page.

Solution:

• I implemented validations on the backend and used fallback: true to handle routes not generated statically:

Lesson:

Dynamic routes require careful validations to avoid broken experiences.

General Front-End Mistakes

Front-end development is not limited to working with specific libraries or frameworks; it also involves applying good design and optimization practices to ensure applications work well on any device and provide a pleasant user experience. Here are some of the most common mistakes and how to fix them.

1. Using fixed measurements instead of responsive units

One of the most frequent mistakes among beginners is using absolute measurements like px to define element sizes in the interface. Although it may seem simple at first, this limits design flexibility and makes it incompatible with screens of different sizes.

Instead, it is better to opt for responsive units like %, em, or rem, which allow elements to adjust automatically according to the size of the container or screen. Complementing this with media queries ensures the design is adaptable and functional at any resolution.

2. Not designing with responsiveness in mind

It is easy to forget that web applications will be viewed from a variety of devices: from phones with small screens to large monitors. Designing only for a fixed resolution can lead to a poor user experience.

The solution is to adopt a mobile-first approach, where the design is built first thinking about mobile devices and then adapted to larger screens. Tools like Flexbox and CSS Grid make it easier to create responsive and organized layouts. Also, regularly testing the design on different resolutions and devices will help you identify problems early.

3. Relying too much on CSS frameworks

Frameworks like Bootstrap or Tailwind CSS can be useful tools to speed up development, but relying completely on them without understanding the fundamentals of CSS can be a costly mistake. This can limit design customization and make it difficult to solve specific problems.

Learning the basics of CSS is essential to have greater control over the design. Once you master the basics, frameworks can be used as support tools, but not as the only solution.

4. Ignoring unit testing

Lack of unit testing can lead to serious errors in production, especially when projects grow in complexity. It is common for beginner developers not to implement tests because they consider them unnecessary or complicated.

Unit tests, performed with tools like Jest or React Testing Library, help ensure that each component or function works correctly before deployment. Implementing them from the start not only improves code quality but also prevents bigger problems in the future.

5. Not using a version control system

Working without tools like Git makes it difficult to track changes made in a project and recover previous versions in case of errors. This problem is especially critical when working in a team.

Adopting Git from the beginning is a fundamental practice. Learning basic commands, such as commit, branch, and merge, will allow you to better organize your workflow, collaborate with other developers, and manage versions efficiently.

Common mistakes when using Git

Even when using Git, it is easy to fall into poor practices. Some common mistakes include:

• Incorrect branch merging: Not performing a merge correctly can cause conflicts that are difficult to resolve. Use commands like git merge and git rebase carefully and make sure to review changes before committing.
• Undoing changes without caution: Commands like git reset or git revert should be used with a clear understanding of their impact. Before undoing something, review the commit history with git log.
• Disorganization in workflows: Adopting clear workflows like GitFlow or trunk-based development improves collaboration and avoids chaos in large projects.

Mastering Git from its basics will give you confidence to handle any situation in your projects.

6. Neglecting resource optimization

A common mistake is uploading images without compression, not minifying CSS and JavaScript files, or not implementing techniques like lazy loading. This can cause long load times, negatively affecting both user experience and SEO.

To solve this problem, use tools like Lighthouse to audit your application's performance and apply strategies such as using modern image formats (WebP), file compression, and reducing unnecessary HTTP requests. Implementing these practices will make your application faster and more efficient.

Conclusion

General front-end mistakes usually arise from lack of experience or ignorance of key best practices. However, correcting them in time and adopting a more conscious approach to development will make a difference in the quality of your projects. By applying responsive measures, optimizing resources, and using tools like Git and unit testing, you will be one step closer to creating robust and professional applications.

Ready to take your front-end development skills to the next level?

At Kranio, we have web development experts who will guide you to avoid common mistakes and adopt best practices from the start. Contact us and discover how we can help you build a solid foundation in your career as a front-end developer.