Full-stack development might be the most controversial discipline in tech. 

The idea of developers working in both client-side and server-side environments seems simple enough. But not everyone agrees on what makes a “full-stack developer.” Some adamantly defend the need for the role. Others are convinced that full-stack developers don’t even exist.

What is clear is that no two full-stack developers are exactly alike. Each represents a unique combination of breadth and depth in front-end and back-end development. But all this complexity can make it confusing to hire full-stack developers or pursue a career in full-stack development. 

And it raises a question: what languages does a full-stack developer actually need to know?

Defining Full-Stack Development

By definition, a full-stack developer needs to know a combination of technologies that allows them to work on both the front end and back end of a website. 

There are two main ways of accomplishing this. The first is to learn one or more languages for each environment. For example, pairing JavaScript with Python.

The second is to use frameworks to extend the functionality of a language to a different environment. For example, using JavaScript for the front end and using Node.js to extend its functionality to the back end.

With that in mind, let’s take a look at the core programming languages full-stack developers need to know.

Front-End Programming Languages

Unlike back-end languages, the options for front-end languages are pretty fixed. The core front-end languages are JavaScript, HTML, and CSS. However, some developers are turning to TypeScript for full-stack development.

JavaScript

JavaScript is a dynamic scripting language used for adding interactive behavior to web pages and applications. The main way developers use JavaScript is to manage the behavior and user experiences of websites. But there are a number of other interesting use cases for JavaScript. Node.js is a framework that extends the functionality of JavaScript to server-side applications. And libraries like D3.js make JavaScript useful for data visualization. There are also a range of powerful JavaScript frameworks, including React, Angular, Vue, jQuery, ExpressJS, and Backbone.

A staggering 97.3% of all websites use JavaScript as a client-side language. And with usage increasing at a rate of 157% per year, JavaScript’s popularity with full-stack developers is only going to grow.

TypeScript

TypeScript is an open-source, object-oriented language that is an extension of JavaScript, meaning JavaScript code is valid TypeScript code. Developed by Microsoft in 2012, TypeScript describes itself as “all of JavaScript, and then a bit more.” 

TypeScript has been gaining popularity for years, and was the fastest-growing programming language in 2022.

HTML

HTML is a standard markup language used for structuring and marking up web pages. While HTML may seem very basic compared to other languages, its ability to structure content has largely created the internet as we know. Necessary for publishing text, headings, tables, photos, and video, HTML is an essential front-end skill. Developers primarily use HTML in conjunction with another front-end language, CSS.

CSS

CSS is a stylesheet language used to design the layout and presentation of web pages. Developers pair CSS with markup languages like HTML or XHTML to control the presentation of web documents. While HTML provides the structure of a page, CSS dictates the style of the page.

CSS frameworks include Bootstrap, Bulma, Foundation, Skeleton, and Tailwind CSS.

Back-End Programming Languages

While the selection of front-end languages is pretty standardized, a full-stack developer’s options for back-end programming languages are pretty open. In theory, a full-stack developer has hundreds of back-end languages to choose from. 

Here, we’ve highlighted the popular, general purpose languages developers often turn to first.

Python

Python is an interpreted, high-level, general-purpose programming language, and one of the most popular languages for rapid development.

There are a number of reasons behind Python’s popularity with developers. It’s easy to learn, usable on nearly every project, and vital for the field of data science. There’s also a range of powerful Python frameworks, including Django, Bottle, and Web2Py. 

For use in full-stack development, Python is a safe choice for a general-purpose programming language. Particularly relevant for full-stack developers is PyScript, which allows them to create front-end applications using Python.

Java

Java is a high-level, object-oriented programming language used to create complete applications. The language is platform independent, allowing it to run on any device that supports its environment. 

This combination of performance and versatility made Java the most popular programming language with developers in 2021 and 2022. You can do just about anything with Java. (Well, almost anything.) 

Like Python, Java is a reliable pick for full-stack developers trying to choose a back-end programming language.

PHP

PHP is a widely-used open source and general-purpose scripting language that is especially suited for web development. PHP’s popularity is owed to the fact that it was one of the first server-side languages that developers could embed into HTML. It’s also fast, secure, versatile, and supported by a strong open source community.

While PHP isn’t as popular as other general-purpose languages, its specialization gives it an advantage in web development over languages like Python.

Go

Go is an object-oriented programming language that Google created in 2009 for networking and infrastructure. But since launch, it’s evolved into a general-purpose language used in a wide range of applications. In 2022, Go was the second fastest-growing programming language, making it a worthy choice for full-stack development.

One framework that’s expanding the language’s full-stack potential is Bud, a full-stack framework used for the fast development of web applications. Known as “Ruby on Rails for the Go ecosystem,” Bud offers a unique combination of simplicity and scalability that helps full-stack developers expand front- and back-end code to meet the needs of users.

C++

C++ is a general purpose, compiled, and statically typed programming language. Known as “C with Classes,” C++ is an extension of C with the functionality of user-defined data classes. 

The high performance of C++ has made it the top language for use cases requiring fast rendering, including browsers, banking applications, and motion design software.

Another major contributor to C++’s ubiquity is its ability to work closely with system hardware. Developers often use C++ as their first choice for hardware-oriented applications, including video game engines, operating systems, and cloud systems. C++ is ideal for full-stack developers who prioritize performance and code reusability.

C#

C# is a general purpose, object-oriented, component-oriented programming language developed around 2000 by Microsoft as part of its .NET initiative. C# is based on the C family of languages, and has similarities to C, C++, Java, and JavaScript. 

An extension of C, C# adds on a number of features, including variable checking, type checking, bound checking, and garbage collection. 

Database Languages 

If you’re working across the tech stack, at some point you’ll need to consider the storage of data, user data in particular. Some, but not all, full-stack developer roles involve database management, which requires competency in a domain-specific query language.

What database language a developer knows will depend on whether they’re working with relational or non-relational databases.

SQL

SQL is an industry-standard structured query language for creating, defining, implementing, accessing, and maintaining relational databases. Usage of SQL is widespread. Not only is it the industry’s go-to query language, it was also the sixth most popular programming language in the world in 2022.

MQL

Non-relational databases store data using a flexible, non-tabular format. Also known as NoSQL (not only SQL) databases, non-relational databases use either SQL or an alternative query language. MongoDB Query Language (MQL) is, unsurprisingly, a query language used for working with the NoSQL database program MongoDB.