Key Engineer (Staff / Principal Level) – Backend, Infrastructure & IoT

Heidi Systems is transforming utility metering in Germany by replacing paper-based processes with an end-to-end digital platform. The company installs meters and gateways in buildings, collects consumption data, and provides property managers with a platform to monitor usage and run yearly utility billing. With paying customers, a growing pipeline, and backing from unicorn founders and directors from Google and OpenAI, Heidi is now seeking a senior technical leader.

As a Key Engineer at Staff or Principal level, you will be one of the technical leads reporting directly to the founders. You will make architecture decisions, build them yourself, and run them in production. Your role encompasses backend services in Go and TypeScript, microservices design and implementation, data pipelines for meter and gateway data, database and storage management, IoT connectivity, infrastructure deployment, and monitoring. As the engineering team grows, you will help hire and mentor the next generation of engineers.

You will own critical systems including the API that powers the SvelteKit frontend, microservices architecture decisions, data ingestion and validation pipelines that feed into customer invoices, PostgreSQL and Supabase database design, MQTT and wireless gateway connectivity, and infrastructure running on Hetzner servers with Docker and GitHub Actions.