Senior Full Stack Engineer, Growth & Experimentation – Krak

• 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.

• 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.

• 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.

Unless a specific application deadline is stated in the job posting, applications are accepted on an ongoing basis. Please note, applicants are permitted to redact or remove information on their resume that identifies age, date of birth, or dates of attendance at or graduation from an educational institution. We consider qualified applicants with criminal histories for employment on our team, assessing candidates in a manner consistent with the requirements of the San Francisco Fair Chance Ordinance.