K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by over $1 billion in total funding from leading investors including Altimeter Capital, ICONIQ, Kleiner Perkins, Lightspeed Venture Partners, Redpoint Ventures, and T. Rowe Price — and with over $1 billion in signed contracts across commercial and US government customers, we're mass-producing the highest-power satellite platforms ever built for missions from LEO to deep space.

The rise of heavy-lift launch vehicles is shifting the industry from an era of mass constraint to one of mass abundance, and we believe this new era demands a fundamentally different class of spacecraft. Engineered to survive the harshest radiation environments and to fully capitalize on today's and tomorrow's massive rockets, K2 satellites deliver unmatched capability at constellation scale and across multiple orbits.

With multiple launches in 2027 and plans to scale to 100 satellites a year, we're Building Bigger — helping develop the solar system and build toward a Kardashev Type II (K2) civilization. If you are a motivated individual who thrives in a fast-paced environment and you're excited about contributing to the success of a high-growth Series D-funded company, we'd love for you to apply.

The Role:

We are seeking an experienced Cybersecurity Architect to support classified programs in direct service to the Department of Defense (DoD) and Intelligence Community (IC). In this role, you will design, develop, and implement comprehensive security architectures for unclassified, CUI and classified information systems operating within K2 Space environments. You will serve as a trusted technical authority, shaping enterprise security strategy, guiding risk management decisions, and ensuring compliance with applicable government cybersecurity frameworks and directives.

Responsibilities

Architect end-to-end cybersecurity solutions for systems across K2 Space, DoD and IC environments, ensuring alignment with mission requirements and compliance mandates.
Lead the design and support the accreditation of systems under the Risk Management Framework (RMF), including the preparation and review of System Security Plans (SSPs), Security Assessment Reports (SARs), and Plans of Action & Milestones (POA&Ms).
Define and enforce security architecture baselines, reference models, and standards across multi-domain and cross-domain environments.
Conduct threat modeling, vulnerability assessments, and security architecture reviews for new and existing classified systems and programs.
Collaborate with program managers, system engineers, and government stakeholders to integrate security requirements into system development lifecycle (SDLC) processes.
Evaluate emerging threats, technologies, and adversarial TTPs; recommend architectural countermeasures and mitigations.
Support Cross Domain Solution (CDS) design, evaluation, and accreditation efforts in coordination with relevant approval authorities.
Provide technical guidance on zero trust architecture (ZTA) implementation within classified environments.
Develop and present security architecture documentation, briefings, and recommendations to senior leadership and others.
Mentor junior security team members and serve as a subject matter expert (SME) on classified cybersecurity matters.

Qualifications

Active Top Secret / SCI (TS/SCI) security clearance with Counterintelligence (CI) Polygraph — must be in-scope and adjudicated prior to start.
8 or more years of cybersecurity experience directly supporting the Department of Defense, Intelligence Community, or other U.S. government national security programs.
Demonstrated expertise in cybersecurity architecture design for classified and sensitive government networks and information systems.
Deep familiarity with NIST SP 800-53, ICD 503, CNSSI 1253, DODI 8510.01 (RMF), and related DoD/IC cybersecurity policy frameworks.
Experience designing or operating within multi-classification-level environments and managing cross-domain data transfer requirements.