React Galaxy Background
React Galaxy Background

most software is
built in silos

Most apps are built using multiple unconnected development approaches. This leads to duplication of teams, duplication of processes, and added complexity to daily work.

Software is only as good
as its surroundings

At Callstack, we believe an app is only as good as the environment it operates in. Which means siloed and dysfunctional organizations tend to create siloed and dysfunctional apps.

We use React Universe
to reverse Conway's law

Thanks to React Universe's cross-platform development approach, we not only help our clients build great apps, but great businesses, by streamlining their teams, simplifying their processes and transforming the way they work.

ConstructionSun and clouds


At Callstack we don’t just ship great code, but help break down structural barriers and remove points of friction across the business.







Architects of React Universe

Callstack is the Total Software Engineering consultancy that develops high-performing cross-platform apps using the React Universe tech stack. We work with global enterprise clients such as PwC, Major League Soccer and AutoZone, and fast-growing startups and SMEs like Evernote and Coinmine.

Tackling the toughest challenges

We make free Open Source tools and libraries that help millions of developers globally build better performing apps quicker and easier.

Leveling up the industry

We help raise industry standards by training developers around the world through business and technology podcasts, articles, and events, including the biggest React Native-focused conference in the world.


To drive and accelerate software development innovation. This informs our values:


We create equal opportunities. We aim at making the technology we co-create accessible to everyone everywhere. We provide an inclusive working environment.


We value the Open Source community. We are happy to contribute to React and React Native ecosystems every day. We encourage knowledge sharing. We develop ideas within our R&D.


We challenge existing solutions. We have the courage and curiosity to challenge the status quo, find innovative solutions and produce something unique. We work on apps used by millions and do projects for various clients.


We constantly seek improvements. We bring passion and energy to work. We are always ready to discuss, challenge and submit ideas. We like to speak about everything React Native in our podcast.


We respect uniqueness and individuality. Everyone is welcome to work with us, take part in our conference or other events. We embrace diversity to keep the workplace healthy and happy.


We strive for perfection in everything we do. We are a team of experts whose goal is to achieve the highest standards. We have a self-development budget for every Callstacker.


We build, maintain and contribute to the most popular Open Source libraries, events and resources in the React and React Native eco-system.