Build native iOS, Android, TV, and desktop apps from one codebase, with native performance and UX and without maintaining a separate team per platform.
AI-Native Engineering
The fastest way to ship React Native products
For over a decade, we've delivered React and React Native for teams with demanding production requirements. Today, we pair that deep expertise with custom AI agents, so you can deliver scopes that would normally require twice the headcount or twice the time.
Why teams pick callstack
Agentic delivery,
led by Core Contributors
AI accelerates the output, but our senior engineers ensure your architecture scales, performs, and works flawlessly in the real world.
One partner across mobile, web, desktop, and TV.
One React codebase covers every platform. Add them now, or bring in later as the product grows.
Complex migrations in quarters, not years.
AI agents handle the repetitive heavy lifting. Our engineers own the core architectural decisions.
Deep engineering for complex native work.
We solve the hardest performance bottlenecks. Your product stays fast and stable as it scales.
Expert execution. Agentic speed.
Feature Development
Scale delivery with AI-native engineering.
Senior product engineers join your team to clear backlog, ship roadmap work, and take high-impact implementation off your internal leads. AI-native delivery lets a small expert team cover more ground without lowering your bar for review, testing, or architecture.
Stacks
React Development
Next.js Development
Expo Development
Node.js Development
One language across frontend, backend, and tooling. Teams ship faster when the API, app, and automation all run on the same runtime and skill set.
Capabilities
Module Federation Development
Generative UI Development
Interfaces composed at runtime from structured LLM output, so the model returns React components instead of plain text.
MCP Server Development
The open standard for connecting agents to internal tools and data. Assistants like Claude Code work inside your systems with the right scope and access.
End-to-End Product Development
Ship every platform from one codebase.
We take full ownership of your product, from architecture to release. One senior AI-native team builds and ships it end to end, so you get to market faster with less delivery complexity.
Apps
Super App Development
Mobile App Development
Web App Development
Streaming App Development
AI-Native
Generative AI Development
Voice Agent Development
Real-time voice interfaces built on speech models and LLMs, where voice replaces tap and type as the primary way users interact with the product.
AI-Assisted Migrations
Execute complex migrations at agent speed.
We move teams off legacy systems without the cost and drag this work used to carry. AI-native workflows make complex migrations easier to plan, execute, and justify.
Technology Migrations
Migration to React Native
Migration to Self-Hosted Infrastructure
Move builds, CI/CD, and delivery off hosted platforms onto hardware you own, with full control over cost, security, and operations.
Migration to Modular Architecture
Break a monolithic app into independently deployed mini-apps that let engineering teams ship in parallel.
Migration to Expo
Move to Expo's managed workflow and EAS infrastructure. Faster builds, simpler releases, and full access to the modern React Native ecosystem.
Migration to Next.js
Move legacy React or SPA apps onto Next.js, adding server rendering, streaming, and edge delivery to the React stack.
React Native Modernization
Migration to New Architecture
Architecture & Performance
Solve your hardest engineering challenges
We help products get past technical limits that slow delivery and hurt quality. Senior engineers solve the underlying issues so teams can ship faster with more confidence.
Performance
React Native Performance Optimization
AI Vibe Coding Cleanup
Native & Low-Level
React Native Modules Development
React Native Brownfield Integration
C++ Library Integration for React Native
Shared Native Core for Cross-Platform Apps
Scope → Build → Scale
The fastest way to ship React Native products.
Scope
We map your problem, align on deliverables, and define success metrics. No surprises once work starts.
Start in weeks, not months
Fixed scope before work starts
1 week
Build
Engineers ship with AI-native workflows from sprint one. Code, decisions, and ownership, not discovery decks.
3 Callstack engineers ship like 6
Impact visible before sprint two
1-12 months
Scale
Expand scope, add platforms, or hand off to your team. The stack, tooling, and raised bar stay with you.
You own everything we build
Move faster on the next launch
AS NEEDED
Case studies
What shipping at AI speed looks like
Open Source
Want to build it on your own?
We open-source the tools behind our delivery model.
Use them, fork them, or let us run them for you.
Insights
Worth your time, by engineers.
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Building Apps Where AI Generates the UI
Most AI apps wrap powerful models in a simple chat interface. This piece explores a different direction: letting the model generate the interface itself. Instead of returning text, it describes what the user should see next. The UI is decided at runtime, adapting to each user and context rather than being hardcoded in advance. The article walks through the architecture behind this pattern and shows it in practice with a project that turns static PDF forms into adaptive, AI-driven interviews.
