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JavaScript
Development
Services

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.

ŁUKASZ KOCZWARA
VP of Engineering

Why choose JavaScript web development services?

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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.

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JavaScript services we’ve provided

to our clients
dynamic website Dynamic website and
web app development
boosting page Boosting page load time
and responsiveness
state-of-art State-of-the-art interactive
components and effects
scalable Improving product reliability
and practicality
icon-projects-delivered Custom plug-in
development
cutting-edge Cutting-edge techniques
to better engage the end users
cross-platform Cross-platform mobile development using
React Native and numerous JavaScript tools
icon-8 (1) Scalable and high-performing
frontend solutions
icon-9 (1) Consulting on choosing the right
frontend technology and frameworks
icon-10 (1) Intuitive, modern, easy-to-navigate
user interface design
icon-11 Smooth user experience
on any browser or device
icon-12 (2) Comprehensive support
and maintenance help

Why work with STX Next?

15 years

of market experience

350+

projects delivered

3+ years

average partnership

130+

clients served

350+

professionals on board

6.5 years

average experience of our JavaScript developers
Co-operation model

Team extension

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.

team-extensions

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.

Which JavaScript
frameworks and libraries

do we have the most experience in?
  • icon-angular Angular
  • icon-react-1 React
  • icon-vue Vue.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.

icon-angular Angular

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.

icon-react-1 React

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.

icon-vue Vue.js

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.

Outsourcing is a big leap for your software projects

On your path to greater velocity and flexibility, we’ve got you covered every step of the way.

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1
What if I want to keep some of the work in-house?

Smart move. By all means, keep your existing team if it works for you. Your external team will simply complement what you’re already doing while bringing in a fresh perspective and greater scalability.

They’re embedded completely in our process to the point that there’s no difference between one of our in-house developers and one of theirs.
Scurri
Software Engineering Manager
2
What if I need to save my budget and cut development costs?

You can scale the team down or move development entirely back in-house.

Not only are they transparent and flexible, but they’ve been immensely helpful when we needed to scale up. When the time came to scale down, it was no problem, either.
Blocktrade AG
CEO
3
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
4
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

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
Blocktrade
Industry: Blockchain & Crypto

Blocktrade

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.

featured in
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read the portfolio entry
project-tiles-3-1
Industry: Internet of Things

NOTA NOTA

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
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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.

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Why is STX Next

the right development partner for you?

developmentpartner
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
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Who trusted us?

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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 were able to scale up instantly, adding developers with the specific technical expertise that we needed and then rotating them out when the problem had been solved. At a much smaller firm that would have been very difficult. So far there hasn’t been any challenge that STX Next hasn’t been able to overcome.

Matthew Brooke-Hitching
CEO @ meet.mba
Featured in gamespot-logo

It was a pleasure working with the team at STX Next. Collaboration and communication worked like a charm and made our first foray into hiring outside help a big success. The developed tool included technology we were able to extract as a library and made the effort even more worthwhile. Looking forward to our next endeavor.

Sebastian Kral
Global Head of Pipeline @ Pixomondo

Working with STX Next felt like a strategic partnership rather than outsourcing. From consultation through to development and delivery, the STX Next team integrated seamlessly within our own team, in a challenging technical area, and delivered to the same standards we expect from our internal developers.

Michael Stone
Chief Technology Officer @ Enroly
Featured in logo-techcrunch-1

STX Next have been working really well with my engineering team. They’re demonstrating great skill, craft, and agile thinking in the way they go about their work, and they’re great people to boot.

Bradley Wright
CTO @ Verve

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 in logo-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

We came to STXnext looking for a partner to join our developers in putting together a site for Buddhist texts. It's a complex project, involving tens of thousands of texts and relations, and dealing with nearly forty languages. We've been more than happy with the process. The STXnext team has shown initiative and interest, and has been quick to adapt to working with our developers.

Bhante Sujato
Director @ SuttaCentral
Featured in forbes

We met STX in the beginning of the latest cryptocurrency boom and their contribution was vital to us when managing that extraordinary demand. They quickly adapt to the company and domain, show true ownership by always acting proactively towards solution and deliver high quality work even under stressful conditions. STX is now one of the most essential partners of our business.

Çağatay Yüksel
Founder and CEO @ Koinim

What other services
do we offer?

Python

DEVELOPMENT SERVICES

Product Design

SERVICES

icon-testing

Software Testing

SERVICES
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