Full Stack Engineer - Growth & Experimentation – Krak

Kraken; Brasil; Remote; BRL 180,000 - 300,000; Full time

Job summary

Kraken is seeking a Full Stack Engineer to join a small growth and experimentation team focused on accelerating acquisition, activation, engagement and trading activity across the Krak app. This frontend-leaning full-stack role centers on React Native and TypeScript to ship fast, lightweight experiments.

You will own experiments end-to-end—hypothesis, design, build, launch, measurement and iteration—while collaborating with Product to improve onboarding, activation and feature discovery to drive

Qualifications

• 3+ years building consumer-facing apps with React/React Native.
• Experience running growth experiments with measurable impact on conversion, activation, retention or revenue.
• Backend proficiency to design and implement services and APIs; open to Rust.
• Strong JS/TS fundamentals across APIs and real-time systems.
• Experience designing and analysing A/B tests with data-driven decision making.
• End-to-end ownership with a strong product engineering mindset.

Responsibilities

• Build and ship consumer-facing features quickly in React Native and TypeScript.
• Own experiments end-to-end—from hypothesis to launch and measurement.
• Improve onboarding, activation and feature discovery to drive conversion and engagement.
• Build viral acquisition and growth features on top of Krak's product offering.
• Contribute to backend services and APIs when experiments require it; Rust exposure welcomed.
• Read results, weigh trade-offs, and decide on scaling or iteration.

Skills

React

React Native

Growth experiments

JavaScript/TypeScript

A/B testing

API design

Mobile performance

Tools

Statsig

Rust

WebSockets

Job description

Building the Future of Open Finance

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.

We’re looking for a 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.

What you bring

• 3+ 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.

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.

Our commitment

Payward is powered by people from around the world and we celebrate the diverse talents, backgrounds, contributions, and unique perspectives that everyone brings to the table. We hire based on merit, seeking out people with the right abilities, knowledge, and skills for the job. We encourage you to apply for roles where you don't fully meet the listed requirements, especially if you're passionate or knowledgeable about crypto.

We may ask candidates to complete job-related skills or work-style assessments as part of our hiring process. These assessments evaluate competencies relevant to the role and are applied consistently across candidates for similar positions. Results are considered alongside experience and interviews, and are not the sole basis for any employment decision.

As an equal opportunity employer, we don't tolerate discrimination or harassment of any kind, whether based on race, ethnicity, age, gender identity, citizenship, religion, sexual orientation, disability, pregnancy, veteran status, or any other protected characteristic as outlined by federal, state, or local laws.

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