Software Engineer – Industrial HMI, Control & Infrastructure (Rust/NixOS) (m/w/d)

About the job

About The Role

ZEEN Tech AG is an award-winning Swiss startup revolutionizing the food industry with our next-generation, water-based frying and drying technology, which we export worldwide. As we grow rapidly, we're looking for passionate individuals to join us.

Instead of relying on legacy, closed-source PLC software, we build our machines' Human-Machine Interface (HMI) and control systems ourselves: a modern Rust stack running on a hardened NixOS base. From the control engine up to the operating system, the entire platform is built on free and open-source software: deliberately so. No vendor lock-in, no black boxes, and full control over every layer of the machine.

We are looking for a Software Engineer to join our team and work alongside our existing Software Engineer. This is a hands-on role: you will take over well-defined parts of the control backend, the HMI, our NixOS machine fleet, and our internal server infrastructure, and progressively take on more ownership as you settle in. You will report to our Software Engineer, who owns the software architecture and will be your mentor. You will also collaborate closely with our mechanical and electrical engineers, the Production Team, and our Culinary Development team, who put the machines through real cooking tests.

Key Responsibilities

• Backend & Control (Rust): Help develop and maintain the machine's core "engine" written in Rust. You will implement and extend the communication layer for our new industrial machines, using robust, scalable protocols (such as Modbus TCP or EtherCAT) to manage a growing network of drives, VFDs, and sensors.
• HMI Development (Rust/Slint): Expand and polish the machine's touch-screen interface, built with Slint, a declarative UI toolkit native to Rust. You will build intuitive controls and real-time data visualizations so operators can easily manage complex, multi-zone thermodynamic processes.
• OS & Deployment (NixOS): Help manage and maintain our operating system environment. The entire machine runs on an encrypted, rootless NixOS setup, packaged cleanly via Nix flakes. You will help keep updates reproducible, secure, and unbreakable across our growing fleet of machines.
• Server & Infrastructure (Proxmox): Administer our in-house Proxmox virtualization cluster: virtual machines and containers, storage, backups, networking, access management, and monitoring.
• Hardware Integration: You won't just be pushing code to a cloud server; your code will spin up massive fans and control 400V heating elements. You will test and deploy your software on actual industrial prototypes on the shop floor.

Requirements & Qualifications

• Experience: Solid experience in software development, with a focus on system-level performance, reliability, and clean architecture.
• Core Skills:
  - Rust: You are comfortable writing Rust or you are an experienced systems developer (C/C++, Go, or similar) genuinely eager to make the switch. You are at ease working with network protocols and low-level communication.
  - Linux/Systems: You are a Linux power user. You either already know Nix/NixOS and functional deployment, or you are excited to master it.
• Mindset: You are a pragmatic problem-solver who enjoys bridging the gap between elegant software architecture and gritty physical hardware, and who is comfortable asking questions and learning fast in a small team.
• Communication: You communicate clearly, work well with colleagues and external partners, and are comfortable working independently and in support of the team.
• Languages: Fluent in English. Any additional language is a plus.

Nice to Have

• A good command of German.
• Experience with modern industrial communication protocols (EtherCAT, Modbus TCP, PROFINET).
• Experience with databases (e.g. PostgreSQL, SQLite, or time-series databases for process data).
• Experience with DevOps practices and CI/CD pipelines: automated builds, testing, and deployment.
• Experience administering servers, virtualization, or self-hosted infrastructure (Proxmox, Docker/Podman, backups, networking), professionally or as a homelab enthusiast.
• Experience building graphical user interfaces. Slint is a bonus, but any declarative UI framework (QML/Qt, Flutter, or modern web frameworks) transfers well.
• Experience designing touch interfaces for industrial machines or embedded devices (e.g., clear status and alarm displays, large touch targets, good readability in a production environment).
• Contributions to free and open-source software projects.
• A background or hobbyist interest in electronics, IoT, or hardware integration.

What We Offer

The chance to work on groundbreaking, next-generation technology that is actively changing the gastronomy and industrial food sectors. Your work will have a direct impact and play a key role in driving our next phases of innovation.A stack built entirely on free and open-source software (Rust, Slint, NixOS, Linux) where you can read, understand, and change every layer instead of filing a support ticket with a vendor.Direct mentoring from the Engineer who owns our software architecture, with room to take on ownership quickly.

• Flexible working hours and the option of partial remote work, combined with regular on-site time in Immensee, where our machines and prototypes are.
• A dynamic, fast-paced environment with quick decision-making and an open feedback culture.

A highly collaborative team culture where mutual support, knowledge-sharing, and a positive workplace environment are our top priorities.

How to apply

Submit your application and ensure you attach the following documents as PDFs:

• Up-to-date CV / Resume: Detailing your relevant work history and skills
• Cover Letter
• Certifications & Degrees