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2247

Oskar Kwaśniewski

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Oskar Kwaśniewski
CEO & Co-Founder of
TesterArmy (2026)
About

Oskar Kwaśniewski is Co-Founder and CTO of TesterArmy, a Y Combinator-backed AI agent platform that automatically tests websites and mobile apps on every GitHub Pull Request.

Before founding

Oskar studied at Zachodniopomorski Uniwersytet Technologiczny in Szczecin, Poland, and built deep expertise as a Senior Software Engineer at Callstack, working on React Native infrastructure and on-device LLMs.

Founder Insights

A prolific open source contributor with 100+ merged PRs to React Native Core, Oskar created widely-used libraries including react-native-visionos and react-native-bottom-tabs, and speaks at React Native conferences on native development and performance.

Experience

Prior to TesterArmy, Oskar was a core contributor at Callstack, pioneering React Native on Apple Vision Pro and visionOS, and co-presenting at global developer events like GOSIM in Hangzhou.

Scale & Impact

TesterArmy, part of the YC P26 batch, generated 500+ signups including Fortune 500 companies from a single viral demo, and launched a CLI tool with integrations for Claude and Codex to power AI-driven testing workflows.

2247

Oskar Kwaśniewski

TesterArmy
Co-Founder
Logo
Oskar Kwaśniewski

Company(s)

TesterArmy

Industry

SaaS

Year Founded

2026

Stage/Funding

Seed

Company Location

us

Connect

About

Oskar Kwaśniewski is Co-Founder and CTO of TesterArmy, a Y Combinator-backed AI agent platform that automatically tests websites and mobile apps on every GitHub Pull Request.

Before founding

Oskar studied at Zachodniopomorski Uniwersytet Technologiczny in Szczecin, Poland, and built deep expertise as a Senior Software Engineer at Callstack, working on React Native infrastructure and on-device LLMs.

Founder Insights

A prolific open source contributor with 100+ merged PRs to React Native Core, Oskar created widely-used libraries including react-native-visionos and react-native-bottom-tabs, and speaks at React Native conferences on native development and performance.

Experience

Prior to TesterArmy, Oskar was a core contributor at Callstack, pioneering React Native on Apple Vision Pro and visionOS, and co-presenting at global developer events like GOSIM in Hangzhou.

Scale & Impact

TesterArmy, part of the YC P26 batch, generated 500+ signups including Fortune 500 companies from a single viral demo, and launched a CLI tool with integrations for Claude and Codex to power AI-driven testing workflows.

About

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