Senior Full Stack Engineer, Growth & Experimentation – Krak - Kraken

About Kraken

Payward — the parent company behind Kraken, NinjaTrader, Breakout, xStocks, Payward Services, and CF Benchmarks — has spent the last 15 years building modern, globally accessible financial infrastructure to advance an open, global financial system.

Founded in 2011, Kraken is trusted by over 10 million individuals and institutions worldwide, offering spot trading, margin, futures, staking, and OTC services.

The Team & Role

We’re looking for a Senior Full Stack Engineer to join a small, dedicated growth and experimentation team within Krak, focused on accelerating acquisition, activation, engagement, and trading activity across the Krak app.

This is a frontend-leaning full-stack role: the majority of your work will be in React Native, supported by enough backend capability to take an experiment from idea to production without waiting on another team. Rather than executing against a rigid roadmap, you’ll work closely with Product on a continuous pipeline of fast, lightweight experiments, owning each initiative from hypothesis through implementation, launch, measurement, and iteration.

The Opportunity

• Build and ship consumer-facing features quickly in React Native and TypeScript, favoring 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 live features.
• Build viral acquisition features and value-add growth features on top of Krak’s existing product offering.
• Contribute to backend services and APIs wherever an experiment requires it. Our backend is primarily Rust; prior Rust experience is not expected, but enthusiasm for learning it is.
• Analyze experiment results, balance conversion trade-offs against key metrics, and autonomously decide whether to scale, iterate, or deprecate features.

What You Bring

• 6+ years of software development experience building and shipping large-scale, consumer-facing applications. Strong, hands-on React and React Native experience is essential.
• Demonstrated experience running growth experiments in consumer-facing environments, with measurable impact on conversion, activation, retention, or revenue.
• Backend proficiency: ability to design and implement services and APIs independently, with strong backend fundamentals and willingness to work in Rust.
• Strong JavaScript/TypeScript fundamentals, with practical experience across APIs, WebSockets, real-time systems, mobile performance optimization, testing, and modern workflows.
• Practical experience designing, launching, and analyzing A/B tests (feature flags, statistical significance, product analytics, funnel and cohort data).
• End-to-end product engineering mindset with high initiative and comfort operating in fast-moving, ambiguous environments.

Nice to Haves

• Customer-facing product experience within fintech, digital banking, payments, trading, or crypto.
• Hands-on experience with Statsig or comparable experimentation platforms for regional and global rollouts.
• Experience programming in Rust.
• Proficiency in SQL and self-serve product analytics.
• Familiarity with AI tools and patterns applied to software engineering workflows.
• Experience in native mobile development (iOS/Android), distributed systems, or microservices architecture.