Twenty is seeking a Senior Data Engineer for an in-office position in its Arlington, VA office to architect and lead the development of data infrastructure that powers our cyber operations applications and capabilities. We're looking for someone with 8+ years of experience in data engineering and architecture, with mastery-level expertise in ETL pipeline development, data lake architecture, and schema design for complex datasets, plus proven leadership experience mentoring engineers and driving technical initiatives. In this role, you'll architect scalable data lakes that aggregate cyber operation data from diverse sources, lead the design of sophisticated graph database schemas that capture relationships across cyber networks, personas, physical world entities, and electromagnetic spectrum data, establish best practices for AI/ML data preparation workflows, and mentor junior data engineers while driving technical excellence across the data platform. You'll join a world-class product and engineering team that delivers mission-critical solutions for U.S. national security, working in both cloud and on-premises environments to build data infrastructure that operates at machine speed. If you're passionate about solving complex data architecture challenges while leading technical initiatives and making a direct impact on national security, we want to talk to you.