Expert JavaScript-focused development with a wide variety of libraries and frameworks to meet your specific frontend needs.

With over 100 JavaScript developers, we are large enough to scale up on demand, yet small enough to value personal relationships.

Examples of our projects
contact us

Expert JavaScript-focused development with a wide variety of libraries and frameworks to meet your specific frontend needs.

With over 100 JavaScript developers, we are large enough to scale up on demand, yet small enough to value personal relationships.

VP of Engineering

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.

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.


JavaScript services we’ve provided

to our clients
dynamic website Dynamic website and
web app development
icon-10 (1) Intuitive, modern, easy-to-navigate
user interface design

Team extension is the simplest way to increase your development capacity. By adding external team members, you can speed up projects in progress or kick off new projects alongside your current work. Think of it as adding new talent to your roster instantly—but at a different office.

  • icon-angularAngular
  • icon-react-1React
  • icon-vueVue.js

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.

How will I know you’re a culture fit?

We’ve been on the market since 2005 and 99% of our clients are outside of Poland, so we have lots of experience cooperating across cultures.

STX Next has very energetic and sociable teams, and we get along well. After working extensively with their teams, we honestly see them as colleagues rather than suppliers. That’s a unique thing, and it has to do with the culture of STX—it’s something they should be proud of.
Hogarth Worldwide
CTO / Product Director
How can I be sure you’ll understand my project and what it needs?

You don’t want to just ship features; your software should help your business succeed in the market. That’s why we’ll begin our cooperation with a discovery process to understand what you’re building, for whom, and why.

They are willing to learn and understand our business. Instead of just coding to our specs, STX Next engages with us as a partner, wanting to understand, improve the code, and deliver better products.
Fintech Company, Austin, TX
Senior Engineering Manager
Examples of JavaScript

projects we’ve delivered

Zappi Project
Industry: Education


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.

read the portfolio entry
Industry: Internet of Things


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.

featured in
read the portfolio entry

All of our case studies

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.

browse all
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 100% 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 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
Thorough grasp of web markup, including HTML5 and CSS3
First-rate ES6 know-how
Hands-on experience in creating unit tests and using JavaScript test frameworks
Truly Agile working environment composed of small, independent teams working in Scrum with a flat organizational structure
Demonstrated experience with multiple modern JavaScript frameworks, like Angular, React, Vue.js, Backbone.js, Node.js, Durandal, Knockout.js, Ember.js, or others
Strong skills in frontend build tools, such as Grunt or gulp.js
Expert knowledge and understanding of JavaScript
Effortless English communication skills
Expertise in using code versioning tools, such as Git
Close familiarity with JavaScript module loaders, such as RequireJS or AMD
Tried and tested use of best JavaScript practices

What our clients say

C-level executives, product managers, tech leads, and founders from around the world have appreciated our help in delivering world-class products under strict deadlines.

The feedback we get from our clients is consistent. We take real ownership. We happily serve as mentors in tech and Agile. We listen to real business needs instead of just shipping features.

We really appreciate working with STX Next, because of their dedication to quality as well as their effort to meet always the deadline - even in a very challenging project phase.

Dr. Holger de Bie
Innovation Manager @ finstreet
Featured inlogo-techcrunch-1

The STX Next team has proven itself to be a solid and reliable partner in software development for the Tiqets platform. Although Tiqets’ main development team is located in the Amsterdam office, having dedicated development teams in Poland gives the company the flexibility it requires in the rapidly growing market that Tiqets operates in.

Sietse van der Laan
Tech Team Manager @ Tiqets

What other services
do we offer?



Product Design



Software Testing

Tell us about your project

Speed up work on your software projects and outpace the competition.

Hire Us
Matthew Harris
Director of Business Dev
Marta Błażejewska
New Business Manager