Backend Developer

• Design and maintain the REST and GraphQL APIs that power scanning, production, and the customer-facing product

• Own services end-to-end: schema design, performance, observability, and the on-call reality that comes with live systems

• Shape architecture decisions as we evolve between monolith and selectively extracted services

• Build async pipelines and queue-based workflows that move data between hardware, production, and customers

• Write code that's tested at the unit, integration, and end-to-end level — and review code with the same standard

• Mentor teammates and raise the bar on security, performance, and GDPR-conscious design

• Collaborate closely with frontend, DevOps, hardware, and product

• Strong PHP and Laravel experience, including Laravel Nova for internal tooling

• Deep MySQL skills — schema design, query optimization, and performance tuning under real load

• Solid grasp of REST and GraphQL API design, plus authentication patterns (JWT, OAuth)

• Comfortable with Docker, Git/GitLab, and CI/CD as part of your normal workflow

• Practical experience with caching, queues, and async processing

• Judgment about when to reach for a microservice and when not to

• A security mindset and the discipline to apply it consistently

Nice to have

• Python or Go (we use both in adjacent systems)

• AWS experience

• Background in data flow modeling or systems where backend meets hardware/IoT

Why Laravel, in case you're wondering

It's a fair question for a company doing what we do. Laravel lets a small team move quickly across a wide surface area admin tooling, customer APIs, internal services without fragmenting the stack. Where we need different tools (Python for ML-adjacent work, Go for performance-critical paths), we use them. The backend is pragmatic, not dogmatic.

Why us?

At Zellerfeld, you will find a multidisciplinary team of engineers, SW and HW specialists, entrepreneurs, designers, and students with a common passion. We embrace contrarian thinking, humility, pushing limits, and improving ourselves. We utilize a flat hierarchy, and we want your voice to be heard. We also care about bonding because we want to be a tight-knit community, so be prepared to spend quality time with everyone, including the CEO!

As a company specializing in both hardware and software, we value close collaboration within our team. Therefore, we are seeking candidates who can join us at our office in Hamburg.