Senior Data Engineer

Location: Chicago, IL or New York, NY

Base Salary Range: $175,000 - $225,000

(Base salary is only one part of Group One Trading's total compensation, which includes an annual discretionary bonus.)

Our Senior Data Engineers build and operate the data platform that powers trading analysis, reporting, and decision-making across Group One. They work closely with traders, risk, finance, and technology teams to understand how data is produced and consumed and turn that understanding into reliable, well-modeled, and well-governed data systems.

Data usage is expanding rapidly across every part of our firm, and we are building a next-generation data platform to support it. Our existing Microsoft-based environment gives us a strong foundation and deep understanding of our data, but much of what comes next is greenfield. You will work closely with our Principal Data Engineer to challenge and refine architectural decisions, build the platform's core components, and thoughtfully migrate existing workloads into a modern data environment.

We are looking for someone who has built modern data systems before and understands the engineering decisions that determine whether a data platform remains reliable and maintainable as it grows.

• Significant professional experience building and operating production data platforms, ideally in financial services or another environment where data accuracy has direct business consequences
• Deep hands-on experience with modern data architectures, including cloud data warehouses or lakehouses, orchestration, transformation frameworks, and streaming or event-driven ingestion
• Expert-level SQL and strong proficiency in Python or another language used to build production data pipelines and tooling
• Strong data modeling skills across analytical and operational use cases, including dimensional modeling and modern alternatives
• Experience building reliable production data systems with automated testing, observability, data quality controls, CI/CD, and infrastructure-as-code
• Working familiarity with the Microsoft data stack-including MSSQL, SSIS, SSAS, SSRS, and Power BI-sufficient to understand and migrate existing workloads
• Ability to contribute meaningfully to architectural decisions, identify trade-offs, and turn agreed-upon designs into production systems
• Sound judgment around implementation choices, migration sequencing, reliability, and production change risk
• Strong communication skills and the ability to work directly with business users to understand how data is actually used

Have you built a modern data platform and learned which decisions matter early, and which can wait? Can you challenge an architecture constructively and then take ownership of delivering it? If so, you may be a strong fit for this Senior Data Engineer position.