Full Stack Data Engineer (m/f/d)

About the company

alcemy is working to reduce the carbon footprint of cement and concrete today, not at some later date. Its mission is to prevent 100 million tons of CO₂ from entering the atmosphere each year by 2030. Since concrete production contributes about 8% of global emissions, the company’s machine-learning software operates directly inside cement and concrete plants around the clock to lower emissions without lowering quality or increasing costs. The product is already in use in about one-third of Germany’s cement plants and more than 30 ready-mix concrete plants.

Role overview

As a Full Stack Data Engineer, you will take ownership of the data foundation that supports the company’s products. That includes everything from taking in raw, messy plant data and cleaning it up, to building the pipelines that power machine-learning recommendations. The role is split roughly evenly between data engineering and backend work, and it involves regular interaction with customers. You will investigate real-world data issues, explain findings clearly to non-technical stakeholders, and make the data onboarding process much easier for clients.

Key responsibilities

• Design, build, and maintain pipelines that collect and clean complex plant data so it can be used by machine-learning systems.
• Contribute to the shift from rigid data requirements toward more flexible, AI-assisted ingestion methods that reduce onboarding friction for customers.
• Investigate unusual data patterns and communicate the results in simple, understandable language to customers.
• Develop and support APIs and PostgreSQL databases that run the company’s products, while helping keep production systems stable.
• Work closely with customers, sales, and customer success teams to bridge technical and non-technical communication.

Requirements

• Strong motivation to contribute to climate action and build work that has tangible impact.
• Hands-on experience deploying Python applications in production.
• Ability to learn an unfamiliar codebase quickly and start delivering value early.
• Comfortable working directly with customers, sales teams, and customer success partners in a patient, clear, and business-friendly way.
• Willingness to use AI tools to improve productivity.
• Experience with Flask, Django, or FastAPI is a plus.
• Experience with PostgreSQL or another SQL database is a plus.
• Exposure to machine learning is beneficial.
• Applicants who do not meet every requirement are still encouraged to apply.

Working style and team culture

The team works collaboratively rather than in isolation. You will own features end to end alongside engineers of different experience levels, covering build, testing, review, and deployment. The environment is fast-moving and startup-like, with a strong emphasis on async communication, prioritisation, transparency, and direct feedback. The company also uses AI tools responsibly: engineers stay accountable for the quality of their work and no AI-generated low-quality merge requests are accepted. The setup is hybrid, based in Berlin Mitte with up to two remote days per week, plus offsites and boat trips. There is also room to grow into either a technical expert path or a management path, with the possibility of leading a product area within a couple of years.

Benefits

• Annual vacation entitlement of 25 days, plus one additional day for every two years with the company, and time off between Christmas and New Year.
• €1,500 per year and three days each quarter for personal development.
• Choice of Mac laptop.
• Office location in central Berlin Mitte.

Compensation and location

The role is based in Berlin Mitte with a hybrid arrangement of up to two days remote per week. The salary range is €60,000 to €75,000 per year, plus VSOP equity.

Tech stack

The backend and data stack is Python-based, including FastAPI, SQLAlchemy, pydantic, pytest, mypy, pandas, polars, numpy, sklearn, and uv for dependency management. Infrastructure includes PostgreSQL, AWS on Kubernetes managed with Terraform, ArgoWorkflows for scheduled jobs, and GitLab for code. The frontend uses React and Next.js with TypeScript, TailwindCSS, Blueprint.js or Radix UI, TanStack Query or axios, and Streamlit for internal tools.

Hiring process

• Introductory conversation with a recruiter.
• Meeting with the hiring manager.
• A take-home assignment based on real work scenarios.
• Technical interview lasting 90 minutes with two engineers, including 30 minutes of live coding.
• Team-fit interview lasting 45 minutes with two future teammates.

Additional information

The company is committed to building a diverse team and evaluates candidates on merit regardless of gender, age, ethnic or national origin, religion or worldview, disability, sexual orientation, or gender identity. People from underrepresented groups in tech are especially encouraged to apply. If any adjustments are needed to participate fully in the hiring process, the company will make reasonable accommodations. Visa sponsorship is not currently available, so candidates must already have a valid EU work visa.