Great backend is nothing without great frontend—and what better way is there to do frontend than with JavaScript?


We’ve been developing frontend in JavaScript virtually as long as we’ve been developing backend in Python. Since we mostly build websites and web apps that require mobile components, up to 90% of our projects involve frontend work.


Over the years, we’ve been recognized by leading authorities in the field like Clutch, Deloitte, or the Financial Times on multiple occasions.


We have 100+ JavaScript developers and 15+ years of experience under our belt to meet your custom JavaScript development needs. We can support your backend development with frontend every time.


Our expert JavaScript specialists will make sure your software project stands out from the crowd and serves your users like no other on the market.







Download our

Introduction Pack

Why choose JavaScript web development services?


JavaScript is essential to not just create, but enhance the frontend. If your project requires any form of responsive frontend design, we can easily develop it using the more advanced UI functionalities JavaScript offers.


A frontend web programming language supported by all modern browsers, JavaScript can also serve as a backend language with the help of Node.js.


We have extensive experience in custom JavaScript development, including the most widely used JavaScript frameworks—Angular, React, and Vue.js—but we’re ready and able to use any frontend tool you require. There’s nothing our frontend developers and Product Design team can’t build for you.


Why work with STX Next?

15 years

of market experience


projects delivered

3+ years

average partnership


clients served


professionals on board

6.5 years

average experience

of our JavaScript developers

Client Reviews


Why is STX Next the right development partner for you?

JavaScript has been our core for over 15 years

Python may have been our first line of business, but JavaScript development services were not far behind, and to this day they remain at the heart of STX Next.

Over 100 JavaScript developers for hire

We may be Europe’s Python Powerhouse, but we also have an unbeatable roster of skilled JavaScript developers. Scale up and down at will with our deep pool of JavaScript experts.

Full range of complementary services

In addition to JavaScript programming, we have everything you need for a long-term, end-to-end tech partnership.

We’re hungry for a challenge

Our reputation attracts the best JavaScript developers you can hire. These top-notch specialists are always out for a challenge, ready to give 120% of their coding skills into any project that needs it.


Dedicated JavaScript development teams

Our teams will work exclusively for you. In the majority of cases, one team sits in one room working on one project, ensuring full focus.

True project ownership

We will build your JavaScript project as if it was our own; our reputation depends on it. We are interested in why you want to build your product, not just what it is or how to build it.

What do we promise if you partner up with us?

A true partnership only works if both sides bring everything they’ve got to the table.


Here’s what you can expect when you join forces with STX Next:


  • outstanding, non-corporate atmosphere, team spirit, and great people to work with;
  • truly Agile working environment composed of small, independent teams working in Scrum with a flat organizational structure;
  • expert knowledge and understanding of JavaScript
  • demonstrated experience with multiple modern JavaScript frameworks, like Angular, React, Vue.js, Backbone.js, Node.js, Durandal, Knockout.js, Ember.js, or others;
  • thorough grasp of web markup, including HTML5 and CSS3;
  • first-rate ES6 know-how;
  • expertise in using code versioning tools, such as Git;
  • tried and tested use of best JavaScript practices;
  • effortless English communication skills;
  • strong skills in frontend build tools, such as Grunt or gulp.js;
  • close familiarity with JavaScript module loaders, such as RequireJS or AMD;
  • hands-on experience in creating unit tests and using JavaScript test frameworks.




Which JavaScript frameworks and libraries
do we have the most experience in?


Developed and maintained by Google, Angular leverages all the strengths of JavaScript to build your product safely and reliably. The framework favors thorough testing and is compatible with multiple platforms, offering a robust and comprehensive package of both tools and design patterns to facilitate the development of your software.

Using the Model-View-Controller pattern, Angular is popular for its clean code structure and two-way data binding, saving you time and making it easy to modify your app. Highly functional, regularly updated, and well documented, the technology’s here to stay.


Created by Facebook for the specific purpose of building interactive user interfaces, React makes the development process effortless and painless. This declarative, component-based library makes your code simpler to write and debug, while smoothly interfacing with other frameworks and libraries.

Modern, well supported, and ever gaining in popularity, React can power mobile apps with React Native and be rendered on the server with Node.js. To make your life easier, it also gives you the option to write new features without rewriting your existing code.


A progressive framework for building single-page applications and user interfaces, Vue.js enriches your product with efficiency and interactivity. Powerful, flexible, and superbly documented, the framework was designed and developed as the modern, future-proof frontend solution from the start, with incremental adoptability in mind.

Vue.js combines many great qualities of other technologies, while staying as open and compatible with the rest of your tech stack as possible. Championing approachability and user-friendliness, it will work well with any other frontend tool you’re using.

JavaScript services we’ve provided to our clients

  • dynamic website and web app development with both tried-and-tested as well as brand-new technologies;
  • boosting page load time and responsiveness;
  • delivering state-of-the-art interactive components and effects;
  • improving product reliability and practicality without sacrificing the aesthetic quality and visual appeal;
  • custom plug-in development leveraging the best JavaScript practices, libraries, and frameworks;
  • incorporating cutting-edge techniques to better engage the end users;

  • cross-platform mobile development using React Native and numerous JavaScript tools;
  • providing scalable and high-performing frontend solutions;
  • consulting on choosing the right frontend technology and frameworks;
  • intuitive, modern, easy-to-navigate user interface design;
  • ensuring smooth user experience on any browser or device;
  • comprehensive support and maintenance help.

Examples of JavaScript projects we’ve delivered


Zappi connects substitute teachers with cover managers at schools.

Using the React Native app, teachers can find jobs, navigate to the school, and get paid for their work through a geofencing solution. They can also receive push notifications and text alerts about new postings.


Featured in Forbes, Blocktrade is a state-of-the-art crypto trading platform prioritizing safety, reliability, and speed.

Simple yet sophisticated, it allows retail users, professional traders, brokers, and institutional money managers to trade with crypto assets and indices in a fully audited, performance-driven, and highly secure way.


Granted the 2018 iF Design Award in the Product category, NOTA NOTA allows you to design, create, and produce your own fragrances.

In addition to the cutting-edge perfume-making machine, the app also offers a social network to share your designs with the world and instantly try out the fragrances designed by others.


During our 15+ years on the market, we have delivered 350+ projects for 130+ clients in several dozen industries, ranging from fintech and big data to education and advertising.

We encourage you to head over to our Portfolio for a broader overview of the companies we’ve worked with.

Who trusted us?

What other kinds of services do we offer?



Matthew Harris

Director of Business Development

+48 512 914 236

Marta Błażejewska

New Business Manager

+48 506 154 343