Heidi Systems

Senior Frontend Engineer

Berlin, Germany full-time Mid Salary not listed
full-time Mid level Technology & IT Curated
Sign in to apply Free account — we bring you straight back to this role.

About the role

About Heidi Systems
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.
We're a small team in Berlin. Product and engineering work directly with the founders, and what you ship lands with real customers fast.
The role
We're looking for a best-in-class frontend engineer. Someone whose code other engineers learn from.
You'll 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.
You'll work closely with our backend engineers and the founders, and you'll help onboard and mentor junior developers and interns as the team grows.
What you'll do
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

What you bring
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

You've 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

You're in Berlin or willing to move, and you're in our office 2 to 3 days a week

How we work
Hybrid in Berlin. You're in the office 2 to 3 days a week. That's 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 you'll 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.

Your next steps
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.

Find more English Speaking Jobs in Germany on Arbeitnow

Interview prep

Walk in with sharper answers.

Use this as a quick practice sheet before you speak with the employer.

Mid
Technology & IT API integration CSS Excel Javascript Mid level full-time

Likely questions

  1. Tell us about work you have done that is close to the Senior Frontend Engineer role.
  2. How would you approach your first 30 days at Heidi Systems?
  3. Which of API integration, CSS and Excel have you used recently, and what did it help you achieve?
  4. Describe a time you solved a problem without waiting to be told exactly what to do.
  5. How do you handle busy days, changing priorities, or pressure at work?

Prepare before the call

  • A recent example that proves your experience with API integration, CSS and Excel.
  • One short story with a problem, your action, and the result.
  • Two examples that show the strengths listed on your CV.
  • A clear reason why this role and company interest you.
  • Your availability, preferred work style, and salary expectations.

Ask them

  • What would success look like in the first 90 days?
  • What are the main problems this hire should help solve?
  • How does the team give feedback and measure good work?
  • What does a normal working week look like for this role?
Practice line

I am interested in the Senior Frontend Engineer role because I can bring practical experience in API integration, CSS and Excel, learn the team quickly, and contribute to the outcomes Heidi Systems needs from this hire.

Related jobs.

More roles from this company or category.