React Native Paper
Material Design for React Native (Android & iOS)
Desktop App Development
Expensify uses agent-device. Mobile bug evidence and profiling are part of its documented usage story.
What you get
Keyboard-first workflows, native window behavior, and high-density layouts, optimized for real desktop usage.
File access, notifications, deep linking, clipboard, menu bars, and other system-level features. It behaves like a true desktop app, because it is one.
Electron with React for most products, react-native-macos and react-native-windows when you need deeper native integration. Logic, design systems, and workflows stay shared with mobile and web.
Assistants, on-device models, and agent integrations like MCP. Desktop unlocks local compute, file access, and OS-level hooks that browsers can't match, and we build apps designed to host AI.
Agents scaffold, refactor, and test in parallel under senior review, so work keeps moving between sessions. You get more shipped per sprint without lowering the engineering bar.
Tuned render paths, startup time, and memory usage. Built to stay smooth with large data sets and complex UIs.
Installers, auto-updates, crash reporting, and platform-specific packaging, including code signing and notarization. Ready for release on macOS and Windows.
Built with handoff in mind: clear structure, documentation, and naming conventions so your team can take full ownership.
How we work together
Our senior engineers join your team to ship features, guide technical decisions, and strengthen delivery.
We take agreed work from technical planning to release, with clear responsibilities and progress you can see.
We address a performance, migration, or infrastructure challenge, or run training around your team’s needs.
Case studies




Desktop App Development
We deliver cross-platform desktop apps without compromising performance or user experience. Let's scope the build.
We had been struggling with React Native application performance until we met Callstack.

We’ll connect you with the right expert within 24 hours.
Still have questions?
Yes. Whether we build with Electron or react-native-macos and react-native-windows, your app gets native window behavior, OS integration, and desktop-grade UX. The same approaches power Visual Studio Code, Slack, Messenger, and Microsoft Teams.
Yes. We use platform-specific extensions where needed, but most of your business logic and UI can be shared across both.
Absolutely. We specialize in setting up shared codebases across mobile, web, and desktop, maximizing reuse while respecting platform boundaries.
Yes. We handle brownfield setups, allowing you to incrementally adopt React Native within an existing desktop codebase.
We handle all the details, from focus management to multi-window handling, so your app behaves exactly like users expect.
Yes. We support building for the Microsoft Store and Mac App Store, including code signing, notarization, and installer setup.
Electron with React in most cases: it's the fastest path to a production desktop app, with the most mature ecosystem, powering VS Code and Slack. When you need a smaller footprint or deeper native UI, we work with react-native-macos and react-native-windows, the stack behind parts of Office and Windows 11.
Yes. We integrate assistants, on-device models, and agent protocols like MCP directly into desktop apps. Desktop gives AI products local compute, file access, and system-level integration that web apps can't match.
Agents scaffold, refactor, and test in parallel under senior review, so work keeps moving between sessions. You get more shipped per sprint without lowering the engineering bar.