(Senior) iOS Engineer - Hardware

As an iOS Engineer on the Hardware team, you’ll build the experiences that connect our SuperApp to the physical devices that power everyday transactions. You'll work at the intersection of hardware, mobile, and real-time communication , ensuring our merchants enjoy a flawless payment experience, no matter the conditions.

This is a hands‑on, high‑impact engineering role where you’ll collaborate across disciplines — from embedded firmware to product design — to bring delightful, resilient, and intuitive device experiences to life. You should be a mobile engineer with a product mindset who can fully own the features you are working on and remain flexible with changing priorities.

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 these 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.

You’ll tackle complex technical challenges, refine our modular architecture, and build elegant, server‑driven UI solutions for diverse markets.

This isn’t just about writing code – it’s about crafting a product with purpose. You’ll have the chance to see your impact at scale, collaborate globally, and deepen your skills in a supportive and innovative environment. Together, let’s redefine what banking can do for small businesses.

What you’ll do

Develop and maintain SDKs and features that connect our iOS app to Bluetooth‑enabled payment devices .

Ensure secure, reliable , and low‑latency communication between hardware and mobile apps.

Own critical flows like device pairing, firmware updates, and transaction handling .

Collaborate with cross‑functional teams (Product, Embedded, Backend, QA) to deliver smooth end‑to‑end payment experiences.

Champion clean architecture , modular design , and robust testing strategies.

You'll be great for this position if,

You have experience building and shipping complex iOS apps or SDKs in both Objective‑C & Swift.

You have good knowledge of architectural design patterns such as MVVM and MVC, and experience ensuring modularized and scalable app architecture

You're comfortable with Bluetooth Low Energy (BLE) and debugging connectivity issues.

You understand multithreading , asynchronous flows , and low‑level APIs in iOS.

You strive for clean code, but also know how to be pragmatic when needed

Your precise communication skills are well suited to working in a distributed team

Why you should join SumUp

Opportunity to work with SumUppers globally on large‑scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office‑first setup