Software Engineer (m/w/d)

The German property management industry is one of the oldest and least digitalised service sectors in the country: file folders, fax machines, no transparency for owners, weeks-long response times, and a chronic shortage of skilled workers.
Most players respond in one of two ways: they sell software to incumbents without experiencing the operational reality, or they buy up existing management firms and bolt software onto paper-based processes. reltix has actively chosen a third path. Inside a single technical infrastructure, we unite operational management and the knowledge that comes from actually offering the service with the digitalisation of data from the properties we manage.
That gives us an operating system for property management: the system teams run on, the source of truth for every property, and the platform workflows and partners plug into.
The result is an AI-enabled service business where requests aren't passed along, they're answered directly. Whether through the manager's software interface, the voice agent on the phone, or the owner's chatbot, because the full context of the property is available everywhere and the system can act on it.
Within the wider real estate industry the property manager acts as a platform between the owner and every single service around the property. From banking, electricity, heating, and internet all the way to major renovation projects, this ecosystem spans every adjacent part of the real estate sector. This unique position allows us to not just provide this infrastructure internally but instead to open it up, so reltix becomes the context layer and the operating system of the entire real estate industry.
Founded in 2025, we've gone from zero to 4,000+ customers and a team of over 30+ people in little more than a year. With funding secured and a third office in Frankfurt planned, we are looking to expand our tech team to help us scale this vision.

We're building the operating system of the real estate industry, and the product is where it all comes together: the software property managers work in, the APIs the voice agent and chatbot run on, the logic that turns a messy real-world request into a clean, automated action.
This is a backend-first role on a small, senior team that ships fast. You'll design the data models, services, and APIs that hold the full context of a property and let every surface act on it, working close to real operational problems with a direct line to the founders on what gets built next. The team is small and the product is broad, so there's plenty of room to go full-stack: if you're curious about the frontend and want to own features all the way to the user, that path is wide open.
Your mission is to own meaningful parts of the product end to end, from data model to API to the feature in production, and to keep a property's full context correct, complete, and instantly available so managers, owners, AI agents, and partners can all act on it.

What you'll do

• Design and build the backend services and APIs at the core of the product: data models, business logic, and the integrations everything else depends on.
• Ship features end to end, from schema and API to the behaviour users experience, and grow into the frontend as far as your curiosity takes you.
• Build the systems that power our AI surfaces, with the full context of the property available to the voice agent, the owner chatbot, and the manager software.
• Integrate with third-party systems across the real estate and financial ecosystem.
• Work directly with the founders and operations team to decide what to build, then ship it fast and iterate.

What success looks like

• In your first weeks, you've shipped real features to production and managers and owners are using them.
• Within a few months, you own a meaningful slice of the backend, and the systems you're responsible for are reliable enough that people stop thinking about them.
• Over time, your reach grows across the stack and into the product decisions, and new engineers build on the foundations you've laid.