Backend Engineer - Data (m/f/d)

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 COz 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.

What you'll do
You'll own the systems that get plant data into alcemy.
That data comes from external partners, and it arrives messy. You'll build and own the
APls and services that take it in, make sense of it, and feed the machine-learning
models behind our recommendations - designing those systems, deploying them,
keeping them running, and diagnosing what went wrong when something upstream
changes without warning.
It's a backend engineering role with a data problem at the centre of it, 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 need is solid production Python, the ability to run what you build, and comfort
talking to the people on the other end of the pipe.

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 know how to deploy, monitor and troubleshoot production systems in a cloud
environment
• You communicate clearly in writing and in conversation, and you collaborate well
across roles
• You're comfortable working directly with customers, sales and customer success -
patient, plain-spoken, and at ease with non-technical enterprise teams
• You pick up unfamiliar codebases quickly, and you're keen to contribute early
• You're open to using Al tools to augment how you work

Nice-to-haves
• Exposure to machine learning or data pipeline projects
• Experience with FastAPI, Flask or Django
• PostgreSQL or similar SQL databases
• Experience designing or maintaining integrations with third-party or partner systems
Don't tick every box? We'd still love to hear from you.

How we work
You won't be working alone - you'll build collaboratively alongside senior and junior
engineers, owning features end to end: build, test, review, deploy.
Small team, direct customer exposure, tast startup pace - so async communication,
clear 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: Al to move fast, engineers always in charge and
accountable, no Al-slop merge requests.
We'll ask you to be flexible. We don't have fixed teams or fixed projects here. As the
business shifts, we'll ask you to move to where the work matters most and pick up new
problems. If you enjoy variety and switching between problems, you'll do well here.
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
• €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 Ul;
TanStack Query or axios; Streamlit for internal tools