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

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

Berlin | Full-Time | Start ASAP

We're looking for an exceptional engineer. A true A-player who wants to take ownership, build world-class technology, and play a key role in shaping the future of Heidi Systems.

About Heidi Systems

Heidi Systems is building the data infrastructure layer for buildings and energy.

We're transforming one of Europe's largest and most outdated industries by digitizing metering, consumption data, reporting, and billing. Our platform connects physical infrastructure with intelligent software, making buildings smarter, operations more efficient, and energy data accessible in real time.

We're a fast-growing, venture-backed startup with real customers, real traction, and ambitious plans to scale.

Now we're looking for a Key Engineer to become one of the technical pillars of our company.

This is not a traditional engineering position. We want someone with exceptional technical depth, strong architectural judgment, and an entrepreneurial mindset. Someone who doesn't just execute tasks but takes complete ownership of complex problems and builds solutions that last.

You'll have the autonomy to make important technical decisions, challenge existing approaches, and help define the engineering foundation of Heidi Systems.

What You'll Own

You'll take ownership of critical parts of our technology and infrastructure, working directly with the founding team.

System Architecture: Design and evolve scalable, reliable backend and infrastructure architectures that can support rapid growth.

Backend Engineering: Build and optimize high-performance services using Go and TypeScript.

Data Infrastructure: Own the ingestion, validation, processing, and transformati