One Codebase, Every Layer

Go full stack for world-class, scalable performance across platforms.

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Full-stack App Development Services

About Callstack

Trusted by

Smarter Development Awaits

We work across the stack all the time, tuning back-end and front-end interactions for maximum efficiency. By optimizing React / React Native apps to communicate seamlessly, we deliver the smoothest experience possible for end users.

Build better apps faster with full stack

Don’t limit your focus to just the frontend or backend. Responsive frontends need equally fast backends. Our unified full-stack approach combines both domains, allowing you to ship smarter, safer apps across multiple platforms—all at once.

Share code and ensure type safety

Benefit from the code-sharing across the React Universe. Our full-stack tactic utilizes TypeScript to ensure type safety throughout, delivering more reliable apps across all platforms.

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Technology we use to deliver full stack apps

Bun

React DOM

React Native

Remix

Node.js

Next.js

Part of

REACT UNIVERSE ECOSYSTEM

Stop juggling multiple languages, platforms, and teams. With React Universe, you get front and back-end, cross-platform power—all in a single programming model.

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what we offer

Our solutions

Multi-Platform Full Stack App Development

Need apps that shine across web, mobile, and desktop? We’ll build them all, end-to-end, ensuring smooth user interactions and efficient database operations. No matter the platform, we deliver experiences that just work.

Legacy Modernization

Struggling with outdated technology and mounting technical debt? We’ll help you modernize with a TypeScript-based approach that’s fast, efficient, and future-proof. Say goodbye to maintenance headaches and hi to streamlined delivery.

SEO & Core Web Vitals Optimization

Want more traffic and higher conversions? Optimized Core Web Vitals mean better user experiences and nearly 33% of the websites pass the CWV threshold (source: Ahrefs). Turn your web app into a search performance powerhouse.

Performance Optimization

Laggy apps don’t stand a chance, do they? We’ll fine-tune your frontend and backend to make your digital product performant. Faster load times, fewer errors, and smoother interactions will keep your users coming back for more.

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What You Can Expect

Impact On Your Product

Faster Development

Simpler development cycles on all platforms
Decreased Time to Market
Quicker app and feature updates

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Better User Experience

Optimized full stack app performance
Improved SEO and Core Web Vitals
Reduced number of issues

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Reduced OPEX

Lower operating costs
Simplified team structures and workflows
Scalability and flexibility

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Future-proof Technology

Universal Javascript/Typescript back-end and front-end frameworks
Trusted & maintained Open Source libraries
Dynamic code loading and global OTA updates

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Why us

We’re co-creators of React Native

and Meta’s partners. By actively helping build the technology, we ensure you’re working with the experts who shape the React Universe. Here, we don’t just build apps - we turn your ideas into reality. From kickoff to launch, our experts work hand-in-hand with your team to ensure everything’s smooth, customized, and simply built to win.

Full-stack Architecture

We provide holistic React architectures connecting clients and servers to avoid overfetching and waterfalls, optimized for maximum performance.

Production-grade Applications

Our apps can handle high user volumes and diverse devices, providing reliable, secure, and high-performance solutions.

Workflow Guidance

Our documentation connects teams and tools, facilitating knowledge sharing and enhancing future maintenance with clear, developer-friendly resources

process

Vision-Led Collaboration

We align with your goals from the start, ensuring every development step reflects your business perspective.

Discovery & Strategy

Our technical experts, PMs, and BAs handle the scope, features, user stories, and deployment plan so you can focus on product growth.

Roadmap
& MVP

We map out the MVP, delivering value fast while laying a solid foundation for future expansion.

Iterative
Delivery

With our first-hand expertise and agile approach, we ensure flexibility and continuous improvement.

Deployment & Support

We manage ongoing deployment, testing, and monitoring, keeping your app future-ready while you stay focused on scaling.

autoZone: Transforming Automotive E-Commerce.

app Performance boost

200%

As a major force in automotive e-commerce, AutoZone operates a complex web and mobile app. By migrating to a full-stack solution with Next.js, we achieved: