React Native Paper
Material Design for React Native (Android & iOS)
Expensify uses agent-device. Mobile bug evidence and profiling are part of its documented usage story.
What you get
One codebase across web, mobile, desktop, and TV. No duplicating AI features per platform.
Managed LLMs, private VPC deployment, or hybrid routing, chosen on latency, privacy, and cost, not hype.
Tracing, cost monitoring, and quality signals built in, so you debug fast and improve release over release.
Permission-aware behavior and guardrails matched to your risk profile, enforced from the first release.
Graceful degradation when connectivity drops. On-device options and caching keep key flows usable.
A UI built around structured interactions and outcomes that fit your product, not a generic chat screen.
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




Generative AI Development
A generative AI feature that survives production: reliable, observable, safe, and on every platform.
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?
We integrate with AWS Bedrock, Microsoft Foundry, Vertex AI, and self-hosted options. We help you choose based on latency, privacy, and cost, not hype.
Yes. We can deploy models inside your VPC or private cloud for maximum control over your data and compliance.
We set up observability that tracks token usage, latency, and cost per feature, so you can optimize spend as usage grows.
We implement structured outputs, validation, retries, and fallback logic to handle failures gracefully in production.
We add permission-aware behavior and guardrails for content filtering, data boundaries, and policy enforcement, matched to your risk profile and enforced from the first release.
Yes. We deliver cross-platform from one codebase, with one team covering UX, integration, observability, and release across every surface.
We set up automated evaluation pipelines that test correctness, grounding, and safety on every release, so you improve outputs release after release.
We build graceful degradation into key flows, with on-device options and caching that keep them usable instead of failing when connectivity is lost.