Senior Frontend Engineer

Heidi Systems builds the energy OS for real estate. We help property managers and owners get their heating water and electricity meters online see consumption in real time and run the yearly utility billing without paper Excel and site visits.

Submetering in Germany is still mostly analog. Meters get read by hand data sits in PDFs and tenants see their consumption once a year. We change that end to end: we install the meters and gateways in the building collect the data and build the web platform property managers work in.

Were a small team in Berlin. Product and engineering work directly with the founders and what you ship lands with real customers fast.

Were looking for a best-in-class frontend engineer. Someone whose code other engineers learn from.

Youll be our senior frontend engineer and own the web platform end to end: architecture code quality and the day-to-day experience of the property managers using it.

The platform is a SvelteKit and TypeScript app. It shows consumption data per building and unit flags anomalies manages tenants and owners and produces the documents for the yearly billing. A lot of it is data-heavy UI and it has to be right because the numbers end up on invoices.

Youll work closely with our backend engineers and the founders and youll help onboard and mentor junior developers and interns as the team grows.

• Own the frontend architecture of our SvelteKit app: routing load functions SSR state and how we talk to the backend via oRPC

• Ship features end to end from a rough idea with the founders to production often before the design is final

• Build the data-heavy parts of the product: consumption dashboards notification rules tenant and owner management billing documents

• Set up and maintain our component library on Tailwind and DaisyUI so the UI stays consistent as we add features

• Raise the bar on quality: strict TypeScript Vitest coverage code reviews a sane PR flow

• Shape the API contract together with backend (types Zod schemas error handling) so frontend and backend stay in sync

• Mentor juniors and interns through reviews and pairing

• 5 years of professional frontend experience ideally at startups or other fast-moving product teams

• 2 years building production apps with Svelte and SvelteKit with a deep understanding of its reactivity model stores lifecycle routing load functions and SSR

• Strong TypeScript: strict mode generics utility types and the judgment to know when types help and when they get in the way

• Hands-on with Tailwind CSS (DaisyUI is a plus)

• Experience with RPC-style APIs (oRPC tRPC or similar) and typed contracts between frontend and backend

• Testing as a habit: Vitest JSDom or comparable tooling

• Comfortable in a Unix environment (Linux or macOS) with Git branches and PRs

• Youve made architecture decisions on a real product and can explain the trade-offs

• You work well with little oversight and ship in small frequent steps

• Fluent English written and spoken

• Youre in Berlin or willing to move and youre in our office 2 to 3 days a week

• Hybrid in Berlin. Youre in the office 2 to 3 days a week. Thats fixed. The rest of the week you work from wherever you like.

• Short paths. You talk to the founders directly most decisions take one call.

• Real ownership. The frontend is yours to shape and youll set many of the standards the team builds on.

• Real impact. Your work runs in buildings across Germany and makes energy use visible where people live.

• Room to grow with the company as the engineering team gets bigger.

If you match most of these requirements and are ready to help digitize the building sector we encourage you to apply. You will join a growing team where your work directly shapes the future of energy management in real estate.