Castellum is a defense-focused technology company headquartered in Vienna, Virginia, delivering services across cybersecurity, software development, systems engineering, and information/intelligence analysis to the federal government. Its threat model is institutional: nation-state adversaries and the technical debt that accumulates inside legacy government systems. The company operates across domains including Electronic Warfare, AI/ML, Data Analytics, Digital Modernization, and C5ISR, giving its teams a broad surface area across the federal mission space.
The financials are concrete. Castellum reported $52.9 million in revenue for 2025, with a record backlog of $273.3 million. Major contract wins include $103.3 million for Special Missions support and $66.2 million for logistics and cyber support services. In its first four years, the company integrated seven acquisitions - a pace that suggests aggressive consolidation of niche technical capabilities rather than organic headcount growth alone.
For security engineers, the operational question is scope. Cybersecurity here isn't a standalone product vertical - it's woven into systems engineering, electronic warfare, and intelligence analysis workflows. That means exposure to full-stack federal environments: network defense and hardening, secure software pipelines, and analytic tooling designed for contested information spaces. The commitment runs toward supporting warfighters, which translates to work where the clearance requirements and technical stakes are both real.
