Software Engineer - Engine Integration

Our Product Engineers are domain experts first, developers second. They build Engines - the simulations and models that capture how buildings actually behave - fast, and increasingly with AI. But these prototypes live on GitHub and only run on laptops: untested against the platform, unavailable to customers.

That’s the gap you close. You’re the key counterpart to our Product Engineers: you understand what an Engine computes, how, and why - well enough to decide where each piece belongs, hand off what belongs to other teams, and build the rest yourself. No finished spec lands in your inbox. You read other people’s code, ask the right questions, and turn a working prototype into a service we can run and trust. We work in a strongly agentic way - so will you.

Your mission

• Run our Engines and make them better - correct, fast, observable. When results look wrong, you can tell whether it’s the data, the integration, or the physics.
• Onboard new prototypes - understand the method and edge cases; judge what’s production-ready and what needs a rewrite.
• Find the right home for each function - decompose monoliths and define the interfaces and data contracts that make those boundaries real.
• Integrate - with Planning and our Systems Architects, translating between domain and platform language, then build what remains yourself.
• Make the next Engine easier than the last - shape the conventions that let prototypes arrive closer to integration-ready.

You won’t do this alone: DevOps, App/Experience, AI, and Data & Flows already own their domains., * Real impact. The Engines you integrate don’t sit in a demo - they feed real investment decisions and move the platform forward in tangible ways.

• The full solution chain. From digital twin to performance monitoring - you work across a complete product portfolio, not isolated one-off projects. Every Engine you bring in has a real place in the whole.
• Flexible working models. Home-office option and a modern office in the heart of Vienna.
• And the day-to-day works too. Daily meal allowance (€5/day), regular team events, free snacks.

• Several years of professional software engineering across the stack, centre of gravity in the backend.
• Python and TypeScript - strong in one, comfortable in the other, attached to neither.
• The ability to read and judge code you didn’t write, including scientific and numerical code.
• A low-ego, collaborative style with domain experts, and the skill to explain trade-offs to people who think in physics, not architecture.
• Professional English. German is a plus, not a requirement.

Nice-to-have

• Geometry in code (computational geometry, meshes, CAD or BIM/IFC).
• Simulation and numerical methods (thermal/energy simulation, FEM/CFD, solvers).
• Real experience with AI and agentic workflows.
• Productionizing research or prototype code (ML pipelines, scientific computing, quant models).
• Building-industry or energy-domain exposure.

OPTIMUSE is a Vienna-based AI startup revolutionizing the real estate and construction industry. We bring insights to the world’s largest asset class that it never had before - both for new developments and existing portfolios. Our AI Hans delivers instant, deep engineering insight into costs, risks and optimization potential, grounded in building physics, simulation and engineering. Backed by international investors and a team of ~25 people from around 10 nations. Become a part of it!