Senior Embedded Software Engineer - Android

About

The Role

As a Senior Embedded Engineer in Sum Up’s Hardware Tribe, you will be part of a small and highly skilled cross-functional team working alongside Hardware Engineers, Product Managers, QA Engineers, and more. You will play a central role in bringing up Sum Up’s next-generation Android-based payment devices — from boot loader and kernel all the way through to framework integration and validation.

About

The Role

As a Senior Embedded Engineer in Sum Up’s Hardware Tribe, you will be part of a small and highly skilled cross-functional team working alongside Hardware Engineers, Product Managers, QA Engineers, and more. You will play a central role in bringing up Sum Up’s next-generation Android-based payment devices — from boot loader and kernel all the way through to framework integration and validation.

This is a relatively new role as Sum Up transitions to the Android platform for its in-house hardware products. Unlike most Android devices, our hardware is a highly customised, security-focused payment device built from scratch — requiring a deep understanding of both embedded hardware and software.

The role is based on-site in our office in Berlin. We believe in the power of face-to-face conversations that happen organically when working next to one another.

About The Team

You have probably used our card readers to buy a cappuccino or pay your hairdresser already. In Hardware, we are passionate about creating beautifully designed card payment devices and accessories that enable our merchants to start, run, and grow their own businesses. In doing so, we deal with a diverse range of engineering topics — industrial and electronic design, embedded systems, all the way to mobile apps and backend services.

We believe in open communication and constant learning over strict rules. If you’re looking for the chance to innovate and help millions of small independent merchants succeed — join us!

What You’ll Do

• Perform system bring-up for the Android Embedded platform, including boot loader, kernel, and driver integration
• Develop and integrate Sum Up custom modules — including kernel drivers, power management, and connectivity components
• Maintain and improve the build system, ensuring stability and scalability across the platform
• Debug hardware and software issues at the protocol level (I2C, SPI, UART, SDIO, etc.)
• Carry out testing and validation to ensure new releases are delivered with the right quality and on time
• Collaborate closely with Hardware Engineers, QA, Product Managers, and Manufacturing/Supply Chain teams
• Independently deliver features on Android OS and contribute to a culture of engineering excellence within the Hardware Tribe

• You have 5+ years of professional experience in embedded systems development with a strong focus on Android & AOSP
• You have hands-on experience debugging hardware interfaces at the protocol level (I2C, SPI, UART, SDIO, etc.)
• You have deep knowledge of the Android OS architecture — from boot loader (U-Boot, Little Kernel) and kernel to the framework and services
• You have expert-level proficiency in C programming for embedded Linux environments
• You have hands-on experience with at least one of the following platforms:
  Qualcomm Snapdragon or Media Tek
• You have solid understanding of embedded security concepts:
  Secure Boot, Trust Zone (TEE), dm-verity, file-based encryption, and hardware-backed key storage
• You have proficiency with embedded debugging tools (e.g., JTAG, logic analyzers, kernel debuggers)

• The opportunity to work on large scale fintech products used by millions of small businesses around the world
• A dedicated annual Learning & Development budget for attending conferences and/or advancing your career through further education
• Enrollment onto our virtual stock ownership program - you will own a stake in Sum Up’s future success
• A corporate pension scheme
• 28 days paid leave + 1 for birthday
• You’ll attend global offsites and/or hackathons.
• You'd enjoy other great benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidized office lunches and other location-tailored benefits, Babbel language platform subscription and more!