Full Stack Engineer - Growth & Experimentation

About the role

Kraken, a crypto exchange founded in 2011 and trusted by over 10 million users, is looking for a Full Stack Engineer to join a small, dedicated growth and experimentation team in Krakow. The team accelerates acquisition, activation, engagement and trading activity across the Kraken app. This is a frontend-leaning full-stack role: most work is in React Native, with enough backend capability to take an experiment from idea to live without waiting on another team.

Key responsibilities

• Build and ship consumer-facing features quickly in React Native and TypeScript, favouring small, high-velocity experiments over long-running projects.
• Own experiments end-to-end: hypothesis, design, build, launch, measurement and iteration, using platforms such as Statsig to test globally or within specific markets.
• Improve onboarding, activation and feature discovery to drive conversion, engagement and trading revenue, iterating rapidly on features already live.
• Build viral acquisition features and value-add growth features on top of the existing product.
• Contribute to backend services and APIs where needed, since the backend is primarily Rust.
• Read your own results and decide whether to scale, iterate or kill, driving technical decisions autonomously.

Required profile

• 3+ years of software development experience building large-scale, consumer-facing applications.
• Demonstrated experience running growth experiments at consumer businesses with measurable impact on conversion, activation, retention or revenue; B2B or platform-only backgrounds are not a fit.
• End-to-end ownership of product features and a product engineering mindset, able to work with minimal direction amid ambiguity.

Required skills

• Strong, hands-on React and React Native experience (essential).
• Working backend proficiency: designing and implementing services and APIs; open to Rust, though prior Rust experience is not expected.
• JavaScript/TypeScript fundamentals, APIs, WebSockets, real-time systems, mobile performance, testing and modern workflows.
• Experience designing, running and analysing A/B tests, feature flags, statistical significance, product analytics, funnels and cohorts.
• Nice to have: customer-facing fintech experience, Statsig, SQL, self-serve analytics, AI fluency, native mobile development, distributed systems or microservices.