Data Engineer - Full Stack (m/f/d)

Berlin Mitte · Hybrid (2 days/week remote) · €60,000–75,000 + VSOP equity

Help us decarbonize cement and concrete - not tomorrow, today.

alcemy is on a mission to keep 100 million tons of CO₂ out of the atmosphere every year by 2030. Making concrete accounts for around 8% of global CO₂ emissions, and our machine-learning software runs inside cement and concrete plants 24/7 to cut it - without sacrificing quality or driving up costs. We're already live in a third of Germany's cement plants and 30+ ready-mix concrete plants.

The role

As our Full Stack Data Engineer, you'll own the data that powers everything we do - the flow of cement and concrete plant data from raw, messy ingestion through cleaning, to the pipelines our machine-learning recommendations run on. The split is roughly 50% data engineering, 50% backend, and it's refreshingly hands-on with customers: you'll dig into real-world data, explain what you find to non-technical people, and make getting data into alcemy dramatically easier.

What you'll do

• Build and own the pipelines that ingest and clean messy plant data into something our ML can use
• Help us move from strict, structured data requirements toward flexible, AI-powered ingestion - so customers onboard with far less friction
• Track down data anomalies and explain your findings to customers in plain language
• Build and maintain the APIs and PostgreSQL databases behind our products, and keep production running smoothly
• Work shoulder to shoulder with customers, sales, and customer success - translating between the technical and the non-technical

Requirements

You'll thrive here if...

Above all, you care about climate change and want your work to count.

Must-haves

• You've deployed production-grade Python applications
• You love getting to grips with an unfamiliar codebase quickly, and you're eager to start delivering work that matters from the start
• You're comfortable working directly with customers, sales, and customer success - patient, plain-spoken, and at ease with non-technical enterprise teams
• You're open to using AI tools to augment how you work

Nice-to-haves

• Experience with Flask or Django and Fast API
• PostgreSQL or similar SQL databases
• Some exposure to machine learning

Don't tick every box? We'd still love to hear from you.

How we work

• No lone warriors - you'll work collaboratively alongside senior and junior engineers, owning features end to end: build, test, review, deploy.
• Small team, direct customer exposure, fast startup pace - so async communication, sharp prioritisation, transparency, and direct feedback are the norm, and how we work is something we shape together, and keep improving.
• We use Claude Code responsibly - AI to move fast, engineers always in charge and accountable, no AI-slop merge requests.
• Hybrid by design (Berlin Mitte office, up to 2 days remote, plus offsites and boat trips), with real room to grow along technical-expert or management tracks - and the chance to lead a product area within a couple of years.

Benefits

• 25 days' vacation - plus an extra day for every 2 years here, and the days between Christmas and New Year off
• €1,500/year and 3 days/quarter for your own development
• The Mac of your choice
• An office in the heart of Berlin Mitte

Our Tech Stack

• Backend & data : Python throughout - FastAPI (auto-generated Swagger/OpenAPI), SQLAlchemy, pydantic, pytest, mypy; pandas, polars, numpy, sklearn; uv for dependencies
• Infra: PostgreSQL, AWS on Kubernetes managed with Terraform, ArgoWorkflows for scheduled jobs, GitLab for code
• Frontend: React & Next.js in TypeScript with TailwindCSS; Blueprint.js / Radix UI; TanStack Query or axios; Streamlit for internal tools

Our Hiring Process is fully remote

• Intro call with our Recruiter
• Meet our Hiring Manager
• A take-home task that mirrors the real work you'd be doing
• Technical interview (90 min) with two engineers, including 30 min of live coding
• Team-fit interview (45 min) with two future teammates

At alcemy, we're building a team as diverse as the industry we're transforming. We welcome applications from everyone and assess every candidate on merit alone - regardless of gender, age, ethnic or national origin, religion or worldview, disability, sexual orientation, or gender identity. We especially encourage people who are underrepresented in tech to apply. If you need any adjustments to take part fully in our hiring process, just let us know and we'll make them.

Note: We don't currently offer visa sponsorship, so you'll need a valid EU work visa.