What is full-stack development?

Digital products, such as mobile and web applications, typically consist of two main components:

• Frontend: the visible part displayed on the client’s device (e.g., in a browser or as a mobile app on a phone)
• Backend: the invisible part that runs on a server, abstracted away from the user. It manages data persistence, user sessions, communication with other systems, and more.

Full-stack development involves building both the frontend and backend of the application—often in parallel.

Traditional team composition in software development

Developing backend and frontend systems requires distinct skill sets.

Backend engineers need to be proficient in the programming language used on the backend, such as PHP, Java, Python, JavaScript (or TypeScript), Go, among others. They must understand the surrounding ecosystem to take advantage of open-source tools and libraries that speed up development. For instance, if they use TypeScript with Node.js, familiarity with web frameworks like Express, Fastify, or NestJS is essential, along with knowledge of databases, scalability, resource management, and systems architecture.

Frontend engineers focus on building user interfaces. At a minimum, they must know HTML, CSS, and JavaScript. Over the past decade, as applications and interfaces have grown more complex, tools like TypeScript, React, and Next.js have become essential. Since browsers only run JavaScript for interactive features (ignoring WebAssembly, which serves a different use case), frontend developers must be well-versed in it. JavaScript is the only native language for web interaction and will likely remain so, given the vast number of websites built with this stack.

Because of these specialized requirements, companies have traditionally employed separate teams for backend and frontend development.

Full-stack team composition in software development

As applications became increasingly complex (think Google, Facebook), engineers found it more efficient to learn both frontend and backend skills rather than focusing solely on one while trying to grasp the full business context of a feature. This led to a shift in team structure: instead of splitting work horizontally (backend vs. frontend), teams began dividing work vertically by features. Fewer people needed to understand a given feature deeply, and those who did could implement it end-to-end.

This gave rise to a new role: the full-stack engineer.

Here’s how I imagine the relationship between business requirements and full-stack development (though individual experiences may vary):

What are the advantages of full-stack development?

• Fewer people need to understand each complex feature.
• Less time is spent on defining and updating API interfaces.
• Reduced communication overhead—no need to sync between frontend and backend teams.
• Team members can be reallocated more flexibly, as all are capable of working on both the frontend and backend.
• Features tend to be more cohesive and better integrated, benefiting the end user who experiences the application vertically (as a whole feature) rather than horizontally (in pieces).
• Often results in faster and more precise implementation.
• Smaller projects that once required two engineers (one for frontend, one for backend) can now be built by one person.
• Encourages more efficient code sharing between frontend and backend.

As mentioned earlier, JavaScript (and its superset, TypeScript) is the only language natively supported in browsers. This means every full-stack developer must know it. Since JavaScript has also been usable on the backend (via Node.js) since 2009, developers who master it and its ecosystem can effectively build both sides of an application.
(For more context, check out our previous articles on the business value of JavaScript and why we love TypeScript).

Naturally, other backend languages can be used in full-stack development when appropriate. For example, Go may be a better choice for high-performance applications, and Python can excel in data-heavy workloads. However, for building applications quickly with maximum code reuse, we typically recommend using TypeScript across the stack.

In the next part of this series, we’ll explore how code sharing and type safety between backend and frontend improve developer experience, reduce development time, and lead to better products.