Senior Android Developer - Global Bank

SumUp enables businesses to get paid easily, process orders quickly, sell online instantly and manage their money more efficiently. We create the tools businesses need to make their business and their customer experience thrive!

As a member of the Global Bank tribe, you’ll play a key part in helping us build SumUp's own digital bank. You’ll be part of a global, autonomous, cross-functional team that takes an aspect of our product and perfect it from concept to execution. Becoming a part of the Global Bank Tribe means working alongside ~250 people with 32 nationalities across Cologne, Berlin, São Paulo, Santiago, Sofia and Vilnius who love to take ownership, work with purpose and help businesses thrive.

As a Senior Android Developer, you'll be part of an experience team that is responsible for building reliable, secure and easy-to-use features inside our mobile app that’s exposed to millions of users across the globe. You’ll empower merchants with a smooth, effortless and engaging banking experience.

What you’ll do

• Design, build, and maintain the mobile banking features to empower our global merchant userbase with smooth and engaging banking operations.
• Work with large scale, highly available and resilient modern systems.
• Write high-quality, clean, and scalable code that meets the highest standards of performance and reliability.
• Participate in architectural discussions, propose solutions, and contribute to the technical roadmap of our Android application.
• Work closely with designers and product owners to build features that are maintainable, usable and beautiful.
• Help us rethink problems we've solved before in a different way as needs evolve and encourage and support continuous learning across the chapter.
• Develop a wealth of knowledge about our complex problem domain as well as its implications in the interface and the backend – and how to manage it in a clean way.

You’ll be great for this role if

• You have native development experience in Kotlin and are experience in building and shipping scalable complex Android applications.
• You have a solid understanding of software design patterns (e.g., MVVM, MVP) and expertise in building modular, scalable app architectures.
• You strive for clean code and know how to write flexible tests that won't break.
• You have expertise with testing frameworks and know how to implement robust test strategies (unit, snapshot, XCUITest, etc.).
• Care deeply about usability, quality, and building seamless user experiences.
• You have a product-focused mindset, enjoy collaborating with cross-functional teams, and take ownership of your work.
• You thrive in a team where you can learn and try new tech, collaborate on technical challenges and grow as a team.

The Tech We Work With

• Language: Kotlin, some legacy code is still maintained in Java
• UI: Jetpack compose - our development features are primarily using XML based designs and you are free to choose compose/xml
• Architectural Patterns: Clean architecture. Navigation controller and single activity arch. MVVM at presentation layer.
• Dependency Injection: Hilt
• Communication: Kotlin Flows and coroutines
• Detekt and checkstyle for code quality check
• Backend Integration: Majority of our tribe integrations are gRPC. 
• Our new features are done using REST - (Retrofit, Okhttp, moshi standard stack)
• Authentication: OAuth
• Firebase: For Analytics, remote config and crashlytics. Grafana for better observability and crash alert integration to slack 
• Testing: JUnit, Mockito and jacoco for reports. UI Testing: We have UI tests for critical flows but we go with pyramid structure where the unit tests are the base and UI tests are at the tip.
• VersionControl: Git and github 

Why you’ll enjoy working at SumUp:

• Be part of a company that values diversity and celebrates unique perspectives.
• Work with a global team of skilled prof