React Foundationused by 50M+ developers100+ Enterprise Clients
Big plans need the right partner.
More platforms. Bigger ambitions. A roadmap that won’t wait. Get the React and React Native expertise to make the right technical calls, with agents and workflows that turn more of your plans into shipped products.
Trusted by 100+ enterprise clients
Expert engineering
Build and scale React Native apps.
Agentic Delivery
Turn AI into better software delivery.
React Foundation
Founding Member
300+ commits to React Native
100+
Enterprise projects delivered
Industry runs on our tooling
50M+
OSS downloads / month
3.7×
Lower task cost vs Opus 5.5
I recommend them as a trusted tech partner for running complex projects.
5x
Faster message
sending time
ISO 27001 certified
Case studies
What shipping at AI speed looks like.
- 3→1
- analytics systems unified into a single interface
- 5
- platforms under one RN codebase: tvOS, FireTV, Tizen, LG, Vizio
- 2.4×
- faster iOS cache-hit builds on average
- 2×
- Estimated AI-assisted delivery speedup
- 4x
- increase in RN pages across the tracked page set
- 3x
- estimated delivery acceleration
- 60+
- components mapped with full Code Connect coverage
- 5x
- faster message sending time
- 10
- min from code change to mini-app release
- 63%
- adoption rate; majority of attendees registered in the app
- 33%
- fewer re-renders across most features
- 6x
- faster builds after replacing Jenkins with EAS
- 2.8x
- increase in knowledge over 8 weeks (25% → 71% assessment scores)
- 2x
- growth in mobile user base during the migration period
- 5%
- faster startup time on FireTV and FireHD devices
- #1
- SEO rank, recovering from 3-9
- 78%
- bundle size reduction (from 50 MB to 11 MB)
- 100k
- weekly downloads on npm
- 130%
- increase in users post-upgrade
Clients
Trusted by enterprise teams at scale.
The team at Callstack are the most experienced engineers in the React Native community.
If you're looking for skilled and trusted React Native developers, Callstack is definitely the way to go.
Their engineers proved to be a crucial part of our mobile app relaunch project.
The trainers are always very helpful and supportive. It really makes a difference!
I appreciate their attention to detail, flexible approach and a high degree of expertise.
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We had been struggling with React Native application performance until we met Callstack.
I recommend them as a trusted tech partner for running complex projects.
Teamworks needed Module Federation, we helped make it real
Not only does Callstack have tremendously talented engineers, but I know they care about the success of the project as much as I do.
