Senior Mobile Engineer

Sezzle; Brasil; On-site; BRL 23,784 - 49,120; Full time

Job summary

Sezzle is seeking a talented Senior Mobile Engineer to join their dynamic team in Brazil. This position offers the opportunity to develop outstanding features for their cross-platform app while working alongside product, design, and backend teams.

The ideal candidate will have significant mobile development experience, particularly with React Native, and possess leadership skills to mentor others. Sezzle is focused on using innovative technology to enhance the user shopping experience.

Qualifications

• 5+ years of professional mobile development experience.
• Deep understanding of React Native architecture and performance optimization.
• Experience delivering mobile applications to app stores.

Responsibilities

• Help own and build out new features within the TypeScript React Native app.
• Manage releases for safe rollout to users.
• Maintain a strong working relationship with product and design.

Skills

Mobile development experience

React Native or similar technology

Mentoring junior or mid-level engineers

Code review

AI (Claude or equivalent)

Education

Bachelor's degree in computer science

Tools

Git

CI/CD pipelines

Testing tools (Jest, Detox)

Job description

The salary range for this role is $4,600 - $9,500 per month (Gross in USD)

About Sezzle:

With a mission to financially empower the next generation, Sezzle is revolutionizing the shopping experience beyond payments, blending cutting‑edge tech with seamless, interest‑free installment plans that make shopping smarter and more accessible. We’re not just transforming payments; we’re redefining how people discover, interact with, and purchase the things they love while driving real impact on merchant sales through increased conversions and higher order values. As we continue to shape the future of fintech and retail, we’re building an innovative, dynamic team passionate about creating more than just a transaction but a truly unique shopping journey.

About the Role:

We are seeking a talented and motivated Senior Mobile Engineer who is best in class with a high IQ plus a high EQ. This role presents an exciting opportunity to thrive in a dynamic, fast‑paced environment within a rapidly growing team, with abundant prospects for career advancement.

What You'll Do:

• Help own and build out new features within our cross‑platform TypeScript React Native app, and Golang backend APIs.
• Manage our releases, using tools like cohorting, feature flags, and app‑store infrastructure to ensure a safe rollout to our millions of active users.
• Maintain a strong working relationship with product, design, and the business to ensure stakeholder needs are being evaluated and met.
• Work with the team to continuously build clean, scalable, robust, and testable code.
• Develop a deep working knowledge of your application, data domain, and KPIs.

What We Look For:

• 5+ years of professional mobile development experience, with at least 2+ years in React Native or similar technology such as Flutter.
• Experience working with native code on iOS (Swift/ObjC) and Native Android (Kotlin/Java).
• Experience developing and delivering a mobile application to Apple and Google’s mobile app stores.
• Deep understanding of React Native architecture, hooks, context, navigation patterns, and performance optimization.
• Strong familiarity with unit testing, integration testing, and E2E testing (Jest, React Native Testing Library, Detox, Appium, etc.).
• Ability to lead features end‑to‑end — from requirements, design, implementation, deployment, monitoring, and improvement.
• Experience mentoring junior or mid‑level engineers.
• Capable of performing high‑quality code reviews with focus on maintainability, clarity, and best practices.
• Drives technical decisions, proposes improvements, and elevates code quality across the team.
• Works well with product managers, designers, backend teams, and QA.
• Demonstrated experience working with Claude or equivalent large language model tools is required; candidates must be comfortable leveraging AI to enhance productivity, research, and communication.
• Bachelor’s degree in computer science.
• Knowledge of mobile CI/CD pipelines (Fastlane, Bitrise, GitHub Actions, etc.).

Preferred Knowledge and Skills:

• Knowledgeable in writing automated tests for applications (unit, integration, end‑to‑end), and implementing them in a CI environment.
• Ability to solve problems with backend‑focused languages like Go, Python, Java or similar.
• Familiarity with typical microservice architecture composed of HTTP APIs.
• Experience working with native code on iOS, Android.

About You:

• You have relentlessly high standards - many people may think your standards are unreasonably high. You are continually raising the bar and driving those around you to deliver great results. You make sure that defects do not get sent down the line and that problems are fixed so they stay fixed.
• You’re not bound by convention - your success—and much of the fun—lies in developing new ways to do things.
• You need action - speed matters in business. Many decisions and actions are reversible and do not need extensive study. We value calculated risk‑taking.
• You earn trust - you listen attentively, speak candidly, and treat others respectfully.
• You have backbone; disagree, then commit - you can respectfully challenge decisions when you disagree, even when doing so is uncomfortable or exhausting. You have conviction and are tenacious. You do not compromise for the sake of social cohesion. Once a decision is determined, you commit wholly.
• Languages: Golang, Typescript, Python
• Frontend: Typescript - React and React Native
• Version Control: Git
• CI/CD: Gitlab
• Testing: Developer‑driven, focus on automated unit, integration, and end‑to‑end tests
• Sezzle is focused on using open source, and we build what we can before buying!