Backend Engineer – POS Platforms Integration

In short

At On, retail isn’t just a channel—it’s an experience. As we scale our global footprint, we’re laying the foundation for a future-ready Point of Sale (POS) ecosystem. To do that, we need robust backend systems that orchestrate flawless integration between the physical and digital, the store and the cloud. We’re looking for a Backend Engineer to drive the integration of our POS platform with mission-critical systems like ERP, OMS, CRM, and loyalty engines. You’ll architect and build resilient services, shape our event-driven data flows, and ensure our store operations stay fast, reliable, and future-proof. Based in Berlin, you’ll be joining the Retail Experience team—where technology meets the shop floor and every request matters. If you love crafting clean APIs, streamlining integrations, and optimizing real-world system performance, you’ll feel right at home.

Your Mission

• Backend & Integration Engineering:

Design, build, and scale backend services that power POS integrations across ERP, eCom, CRM, inventory, and loyalty platforms Develop REST and GraphQL APIs that are performant, secure, and easy to consume Implement real-time and batch data sync, authentication flows (OAuth, SSO), and secure event pipelines

• Architecture & Resilience:

Contribute to the design of a cloud-native, event-driven architecture for global retail operations Build scalable integration patterns using message queues (Kafka, RabbitMQ) and serverless workflows Support observability through proactive monitoring, alerting, and performance tuning (e.g., NewRelic)

• Testing & Quality Automation:

Ensure reliability through a robust automated testing stack: contract tests, load tests, and test data pipelines Collaborate with QA and DevOps to streamline CI/CD and improve release confidence Participate in incident response and post-mortem analysis to continuously harden platform stability

• Collaboration & Strategy:

Partner with frontend, product, and vendor teams to align integration design with platform capabilities Influence technical decisions during vendor evaluations and rollout phases Impact roadmap decisions by sharing technical insights and platform implications Actively contribute to the broader architecture vision for On’s composable commerce technology stack

Your story

• 3+ years of backend engineering experience with modern technologies (Node.js, TypeScript, or similar)

• Proven track record integrating APIs across commerce, ERP, OMS, or CRM domains

• Familiar with headless commerce, microservices, and composable architecture principles

• Experience with message brokers (Kafka) and asynchronous data processing

• Solid understanding of databases (e.g., PostgreSQL) and infrastructure-as-code tools (Terraform)

• Skilled in designing, scaling, and monitoring cloud-native services (AWS, GCP, or Azure)

• Familiarity with OAuth2, token-based authentication, and secure service design

• Strong debugging and telemetry skills: logs, traces, metrics, and real-time alerting

What to expect

We want to set everyone up for success, so here’s the lowdown on how we hire. Our process is a two-way street – bringing you into our culture, while helping us learn how you think.

Our full process can last about eight weeks from application to offer, because we care about getting it right. These steps explain how we usually do things.

Before you get started, feel free to consider if you want to work with us. Strange question? Well, we give people a lot of space to navigate their day-to-day and that style isn't for everyone. We want you to be passionate about what you do and be sure this is the right fit. Because when skills and passion combine – it creates that 'Wow' moment.

• Step One

  It starts with you...

  You'll start by submitting your application to a specific role. We try to keep this step as simple as possible. We do get a lot of applications, but we review them all. We ask that you allow around 14 days for us to come back to you with a response. If you are a good fit to the role, someone will follow up with you within that window. If you didn't receive a reply, or were unsuccessful this time around, we encourage you to look for other possible matches at On.

• Step Two

  Interview with a recruiter

  What ignites your spirit? This is where we’ll start getting to know all about you and what makes you tick – and it’s your first chance to get a feel for our culture. Chatting with a member of our talent team, you’ll learn more about On and how we work. We’ll learn about what motivates you and what you could bring to the team.

• Step Three

  Interview with a hiring manager

  Ready to dig into the details? This second interview will be held with your future manager and will focus on the specifics of the job. Together you’ll delve into your unique skills and experiences and how they could be relevant at On. It's also a time to assess how you might feel working side-by-side. Bring any questions you have about the job, the team or anything else you might like to know – this is an open forum.

• Step Four

  The Case Study

  What's your style? This task will help us understand how you think, face a challenge and give insight into your novel ideas. Designed to give everyone their best shot, your case study is based on something you might typically experience on the job. This is your chance to show us what you’ve got. So express yourself. Be you.

• Step Five

  The Experience Day

  Your first taste of the Oniverse. This is a time to meet some of the people you'll be working closest with. In person or virtually, you'll get a feel for the day-to-day at On and the people who make it happen. You'll chat with a few potential teammates - the conversations will be as equally driven by the role and your experience as by our values. We believe how you do things is just as important as what you do.

• Step Six

  The Result

  Are we a good fit? We’ll get together internally to share our feedback and decide if we’re a match. We know that job searching is a big time investment, so it’s not a decision we take lightly. It’s also time for you to reflect on the experience – are we the right place for you? No matter the outcome, we’ll give you meaningful feedback.

Step One:

It starts with you...

You'll start by submitting your application to a specific role.

We try to keep this step as simple as possible. We do get a lot of applications, but we review them all. We ask that you allow around 14 days for us to come back to you with a response. If you are a good fit to the role, someone will follow up with you within that window. If you didn't receive a reply, or were unsuccessful this time around, we encourage you to look for other possible matches at On.