Freelance Data Engineer | AWS, dbt, Airflow, Terraform | Data Lakehouse & Analytics Engineering

3/2024 – 9/2025

· Took full ownership of Xentral’s internal BI backend, covering data domains like finance, RevOps, and operations; managed the supporting infrastructure using Terraform.

· Cut costs by 25% and boosted performance by migrating ETL pipelines from Glue to Athena and ECS.

· Co-led the adoption of Apache Airflow, data quality tests, and Iceberg tables, reducing data quality issues to zero.

· Designed and launched Xentral’s first event-driven data pipelines, enabling sub-minute updates for key metrics.

· Developed and maintained services in Go, including a production-grade exchange rate service documented with OpenAPI.

· Designed the data products powering 20+ internal dashboards, working closely with Looker users to align with business needs.

· Set up centralized data cataloging via a custom metadata repository, syncing documentation to Confluence, AWS Glue, and Looker for internal and in-product data visibility.

· Modernized internal tooling and workflows, enabling the company to scale operations with minimal overhead.

· Automated marketplace listings, including direct wholesaler-to-consumer offers, eliminating manual listing work entirely.

Amazon Web Services (AWS), Python, SQL

5/2022 – 4/2024

· Built and maintained ETL pipelines using Glue Workflows, supporting 100+ internal users.

· Collaborated closely with business and product teams to shape pipelines and models around real needs.

· Led the migration from internal subscription systems to Chargebee, enabling scalable and auditable billing.

· Launched foundational infrastructure and processes across business domains including Finance, RevOps, and Operations.

· Drove early adoption of scalable cloud data tooling, laying the groundwork for later performance gains and automation.

Amazon Web Services (AWS), Python, SQL

7/2019 – 3/2022

· Promoted from working student after demonstrating ownership and delivering high-impact features across core systems.

· Built a custom ERP system from scratch using Flask, HTML, CSS, and JavaScript to support all business operations.

· Designed and implemented a dynamic pricing engine integrated with marketplace APIs, reducing daily manual adjustments by 95%.

· Automated procurement and inventory workflows by integrating with 5+ wholesaler APIs, cutting fulfillment delays and reducing processing time from hours to under 10 minutes.

· Modernized internal tooling and workflows, enabling fully automated marketplace listings—including direct wholesaler-to-consumer offers—with minimal manual effort.

HTML, JavaScript, Python, SQL, Web Entwicklung