Senior Full Stack Engineer, Growth & Experimentation - Krak

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 live 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 one from hypothesis through implementation, launch, measurement and iteration. The mandate is simple: find the highest-leverage opportunities to grow users and revenue, prove what works, and scale the winners - with direct, measurable impact on how millions of customers discover and use Kraken’s products.

The opportunity

• 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 that are already live.
• 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, so you can ship across the stack without being blocked. Our backend is primarily Rust; prior Rust experience is not expected, but enthusiasm for picking it up is.
• Read your own results, including trade-offs between conversion gains and other metrics, and decide whether to scale, iterate or kill - driving technical decisions autonomously amid evolving priorities and limited upfront planning.

Benchmarking, Financial Systems, Global Financial Markets, Cryptography, Futures, React Native, User Interface/Experience (UI/UX), Revenue Growth, Customer Relations, Onboarding, * 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 at consumer-facing businesses, with measurable impact on conversion, activation, retention or revenue. This is a consumer growth role, so B2B or platform-only backgrounds are not a fit.
• Working backend proficiency: you can design and implement services and APIs yourself. We care about backend fundamentals rather than any particular language, and you should be open to working in Rust.
• Strong JavaScript/TypeScript fundamentals, with hands-on experience across APIs, WebSockets and real-time systems, mobile performance, testing, and modern development workflows.
• Practical experience designing, running and analysing A/B tests - feature flags, statistical significance, product analytics, funnel and cohort data - with the judgement to act decisively on what the results show.
• End-to-end ownership of product features and a strong product engineering mindset, with the initiative and adaptability to operate with minimal direction amid ambiguity and frequently changing priorities.

Nice to haves

• Customer-facing product experience within fintech, digital banking, payments, trading or crypto.
• Hands-on experience with Statsig or a comparable experimentation platform, including regional and global rollouts.
• Rust experience, given our backend stack.
• SQL and self-serve analytics, so you can pull and interrogate your own data.
• AI fluency. Familiarity with how AI tools and patterns have fundamentally shifted your development workflow and problem-solving approach.
• Native mobile development (iOS/Android), distributed systems or microservices, or engineering within a hyperscaling consumer technology organisation.

Payward - the parent company behind Kraken, NinjaTrader, Breakout, xStocks, Payward Services and CF Benchmarks - has spent the last 15 years building one of the most modern and globally accessible financial infrastructure platforms in the industry, built to advance an open, global financial system.

The team

Founded in 2011, Kraken is one of the world’s longest-standing crypto platforms, trusted by over 10 million individuals and institutions across the globe. It offers spot trading, margin, futures, staking, and OTC services, with products built for both individual investors and institutional clients.