Cybersecurity Architect, (TS/SCI), CI Poly

K2Spacecorporation; Los Angeles (CA); On-site; USD 180,000 - 280,000; Full time

Job summary

K2 Space is seeking an experienced Cybersecurity Architect to support classified DoD/IC programs. You will design, develop, and implement comprehensive security architectures for unclassified, CUI, and classified information systems within K2 Space environments.

You will serve as a trusted technical authority, guiding risk management decisions and ensuring compliance with applicable government cybersecurity frameworks and directives.

Qualifications

• Active TS/SCI security clearance with Counterintelligence (CI) Polygraph (in-scope)
• 8+ years of cybersecurity experience supporting DoD/IC programs
• Expertise in security architecture design for classified government networks and systems
• Proficiency with RMF and related DoD/IC cybersecurity policy frameworks (NIST SP 800-53, ICD 503, CNSSI 1253, DODI 8510.01)

Responsibilities

• Architect end-to-end cybersecurity solutions for DoD/IC environments
• Lead RMF accreditation activities including SSPs, SARs, and POA&M
• Define security baselines and reference models across multi-domain environments
• Conduct threat modeling and security reviews for classified systems
• Collaborate with program managers and government stakeholders to integrate security into SDLC
• Evaluate emerging threats and propose architectural countermeasures
• Provide guidance on zero trust architecture in classified environments
• Present security architecture findings to senior leadership
• Mentor junior security staff and serve as SME on classified cybersecurity

Skills

Cybersecurity architecture

RMF/DoD policy

Threat modeling

Security governance

Leadership/mentoring

Job description

K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by $450M from leading investors including Altimeter Capital, Redpoint Ventures, T. Rowe Price, Lightspeed Venture Partners, Alpine Space Ventures, and others - with an additional $500M 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 planned through 2026 and 2027, we're Building Bigger to develop the solar system and become 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 groundbreaking Series C space startup, 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&M).
• 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.
• Proficiency in network security architecture, including segmentation, firewall policy, PKI/encryption, and intrusion detection/prevention.
• Strong understanding of endpoint security, identity and access management (IAM), and Privileged Access Management (PAM) in government environments.
• Proven ability to lead technical security architecture efforts and communicate findings to both technical and executive audiences.

Nice to Have

• Experience with zero trust architecture (ZTA) implementation in accordance with DoD ZT Strategy and NIST SP 800-207.
• Familiarity with NSA-approved cryptographic solutions and key management systems used in classified environments.
• Experience supporting all levels of classified programs.
• Background in cloud security architecture within classified environments (e.g., AWS C2S, Azure Government, or equivalent IL5/IL6 environments).
• Experience with Cross Domain Solutions