React Native Testing Library
Simple and complete React Native testing utilities that encourage good testing practices
18.2M downloads/mo
Industry runs on our tooling
50M+
OSS downloads / month
React Foundation
Founding Member
300+ commits to React Native
2.8x
Knowledge increase
over 8 weeks
100+
Enterprise projects delivered
ISO 27001 certified
Agent Skills
Callstack’s engineering practices packaged as reusable instructions for coding agents.
What you get
Training that changes Monday morning.
Hands-on, in your codebase
Exercises on your real repositories and tickets, not toy examples.
Agent workflow mastery
Planning, delegating, and orchestrating agents beyond autocomplete.
Context engineering
Structuring repos, docs, and skills so models perform.
Judgment and review habits
Validating AI output fast without rubber-stamping it.
Role-based tracks
Different depth for seniors, juniors, and leads.
Practice that sticks
Office hours and follow-ups after the workshop, so habits survive deadlines.
How we work together
Training shaped around your team, codebase, and roadmap.
Extend your team
Our senior engineers join your team to ship features, guide technical decisions, and strengthen delivery.
- Your roadmap and workflow
- Expertise shared as we work
- Flexible timezone coverage
Deliver a project
We take agreed work from technical planning to release, with clear responsibilities and progress you can see.
- 3 Callstack engineers ship like 6
- Impact visible before sprint two
- End-to-end delivery
Solve specific challenge
We address a performance, migration, or infrastructure challenge, or run training around your team’s needs.
- Focused reviews or implementation
- Knowledge your team keeps
- Outcomes guaranteed with contract
Case studies
What shipping at AI speed looks like.
- 2.8x
- increase in knowledge over 8 weeks (25% → 71% assessment scores)
AI Developer Training
Train like the teams that ship with agents.
Practical AI engineering skills, taught by people who use them in production.
We had been struggling with React Native application performance until we met Callstack.
Train my team
We’ll connect you with the right expert within 24 hours.
Still have questions?
Let’s find the right path for your product.
What level do engineers need?
Any. Tracks split by experience: juniors build fundamentals and safe habits; seniors focus on orchestration, architecture, and review at agent speed.
Remote or on-site?
Both. On-site accelerates the hands-on parts; remote works well for distributed teams. The format follows your team, not our preference.
How large can a cohort be?
Around ten keeps it interactive; larger groups split into parallel cohorts with the same curriculum.
How long is the program?
Typically two to five days of workshops spread over weeks, plus follow-up office hours. Compressed formats exist for leadership overviews.
Is it tied to specific tools?
Grounded in the tools you actually use - Claude Code, Cursor, Codex - with technique that transfers when tools change.
How do we know it worked?
Pre and post signals: adoption, acceptance rates, and rework on trained teams. Pair it with the Adoption Dashboard and the delta is visible.
