Senior Data Platform Engineer

• Hi, I'm Erik, CTO at Circonomit. We build the decision platform industrial companies use to plan their production. Three problems on my table right now:
• Users need to explore millions of records without the UI slowing down, even while an optimization model runs over the same underlying data.
• The UI and the solver need that data in different shapes and on different timescales. Our data models and query paths have to serve both.
• Customer data arrives through ERP exports, Excel files, and CSVs. It has to become one consistent, queryable model, with each tenant's data reliably isolated.
• I need someone to take the data platform and own it end to end: decide what it needs, build it, keep it running.
• Our models decide what gets produced when, on which machine, and at what stock level. Every one of them runs on the data you would own.
• We came out of RWTH research, raised €2.8M with Vorwerk Ventures, and have customers running on our models today. Small team, Cologne office.

Requirements

• 5+ years working on production backend or data-intensive systems.
• Recent, substantial hands-on experience writing and operating production software.
• Strong Python skills. TypeScript experience is a plus.
• Production PostgreSQL experience: multi-tenancy, migrations, and performance optimization.
• Deep SQL knowledge and experience with analytical data processing, such as columnar formats or embedded query engines. We use Parquet, Arrow, and DuckDB.
• Experience building, extending, and maintaining ETL pipelines across heterogeneous sources, including ERP exports, Excel, and CSV.
• Experience setting up and maintaining CI/CD pipelines for reliable production deployments.
• The ability to make technical decisions independently and explain the trade-offs.
• German at C1 level or above, and fluent English. Team communication is in German; code and documentation are in English.
• The right to work in Germany. We do not offer visa sponsorship.
• You should enjoy turning ambiguous customer needs into clear technical priorities, rather than waiting for fully specified tasks. Priorities can change as we learn from customers; you'll work directly with me to make scope and trade-offs explicit.

Benefits

• Ownership.
• The whole data platform: ingestion, storage, query paths, and deployments.
• Architectural influence.
• You'll own the evolution of our data platform: what to keep, what to improve, and where to introduce new approaches. You'll make those trade-offs directly with me.
• Real-world impact.
• Customers plan their production on our models today.
• Direct collaboration.
• Small team, no org chart between you and the founders. Weekly feedback, both ways.
• Compensation.
• Competitive salary plus a VSOP package reflecting your contribution and development in the role.
• Hybrid work.
• We work from our Cologne office, with one to two home-office days per week. You don't need to live in Cologne, but you do need to be able to work from the office on the remaining days.
• Your setup and everyday extras.
• Hardware of your choice · AI tooling budget · sports membership · Deutschland-Ticket.
• Process:
• A 20-minute call, a technical conversation, a three-hour challenge with a 45-minute walkthrough, then a conversation with the team. Two to three weeks overall, with feedback within days.