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Twenty

Autonomous offensive cyber operations platform

IT Security Engineer

Full-Time
$116k - $195k/yr
Senior
Bachelor's
Arlington County, Arlington, VA, USA
In Person
CybersecuritySecurity Engineering & Architecture
No H1B Sponsorship
US Citizenship Required

About the job

Requirements
  • A bachelor's degree in Computer Science, Information Security, or a related field, or equivalent professional experience.
  • At least 5 years of professional IT security experience, with demonstrated expertise in at least two of network security, systems security, or cybersecurity.
  • Strong knowledge of TCP/IP, DNS, DHCP, and network protocols, with experience using firewalls, proxies, and network segmentation.
  • Hands-on experience with security tools such as Splunk, ELK Stack, Snort, Suricata, or similar SIEM and IDS/IPS platforms.
  • Proficiency in systems security, including endpoint protection and vulnerability management.
  • Experience with cloud security (AWS, Azure, or GCP) and containerized environments (Docker, Kubernetes).
  • Understanding of common attack vectors and security frameworks such as NIST, CIS Controls, and OWASP Top 10.
  • Strong problem-solving skills and the ability to work independently and as part of a team.
  • Strong communication skills to explain complex security concepts to non-technical stakeholders.
  • U.S. citizenship is required.
Responsibilities
  • Design, implement, and maintain enterprise network security architecture, including firewalls, intrusion detection systems, VPNs, and DMZs.
  • Develop and enforce security policies, standards, and procedures across the organization.
  • Conduct security assessments, vulnerability scans, and penetration testing to identify and remediate security gaps.
  • Monitor systems and networks 24/7 using SIEM tools, and investigate and respond to security incidents.
  • Manage access controls, identity and access management, and multi-factor authentication solutions.
  • Establish and manage data loss prevention and encryption protocols for sensitive data at rest and in transit.
  • Perform security hardening of servers, workstations, and endpoints; manage patch management and system updates.
  • Provide security awareness training and education to employees.
  • Conduct root cause analysis on security incidents and prepare incident response reports and recommendations.
  • Ensure compliance with relevant regulations and standards, including CMMC, SOC 2, GDPR, PCI-DSS, or applicable industry-specific standards.
Desired Qualifications
  • Security certifications such as CISSP, CISM, CEH, CCNA Security, Security+, or similar.
  • Experience with security automation and Infrastructure as Code tools such as Terraform and Ansible.
  • Knowledge of application security testing (SAST/DAST) and secure development practices.
  • Experience with incident response and forensic investigations.
  • Familiarity with compliance frameworks and audit processes.

About the company

Twenty builds and deploys intelligent, autonomous systems for offensive cyber operations used by the U.S. military and Intelligence Community. Its software automates the offensive cyber lifecycle across hundreds of targets, turning multi-week workflows into continuous operations. The company emphasizes enterprise-grade, scalable cyber power to move beyond defensive postures and support active cyber conflicts, supported by government contracts and investors. Its goal is to provide faster, more reliable automated tools that give operators an information edge for national security missions.

Company Size

51-200

Company Stage

Series B

Total Funding

$168M

Headquarters

Arlington, Virginia

Founded

2024

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Simplify's Take

What believers are saying

  • Reuters reported June 17, 2026 that Twenty raised $100 million at a $1 billion valuation.
  • The round brought $138 million total funding, extending runway for engineering hires and product hardening.
  • Cyber Command's $12.6 million ceiling and Navy research work provide reference customers and credibility.

What critics are saying

  • Twenty depends on federal procurement; a budget pause or protest stalls revenue immediately.
  • Offensive cyber products invite congressional scrutiny, legal restrictions, and public backlash after any mishap.
  • Crowded defense-AI rivals like Accel-backed startups and Prime targeting similar agency buyers compress differentiation.

What makes Twenty unique

  • Joe Lin and Leo Olson pair Palo Alto Networks product chops with U.S. military tradecraft.
  • Twenty won a sole-source U.S. Cyber Command OTA in June 2025, validating mission fit.
  • The platform targets autonomous offensive workflows, compressing weeks of cyber ops into continuous execution.

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Benefits

Health Insurance

Dental Insurance

Vision Insurance

Life Insurance

Disability Insurance

Parental Leave

Unlimited Paid Time Off

Paid Holidays

401(k) Retirement Plan

Health Savings Account/Flexible Spending Account

Commuter Benefits

Growth & Insights and Company News

Headcount

6 month growth

6%

1 year growth

20%

2 year growth

20%
Citybiz
Jul 20th, 2026
Twenty secures $30M from Khosla Ventures at $1.2B valuation for AI cyber warfare tech

Cybersecurity startup Twenty has raised an additional $30 million from Khosla Ventures, bringing its valuation to $1.2 billion. The investment follows the company's recent $100 million Series B led by Accel, which valued it at $1 billion. Founded in 2024, Twenty has now raised a total of $168 million from investors including Khosla Ventures, Accel, General Catalyst, In-Q-Tel, Point72 Ventures, Caffeinated Capital and Friends & Family Capital. The company develops AI-enabled offensive cyber capabilities for the US military and intelligence agencies. Its technology combines artificial intelligence, automation and human oversight to support cyber operations whilst maintaining human decision-making throughout mission execution. Chief executive Joe Lin said the funding will support investment in engineering and product development as the company expands its technical workforce.

Accel
Jun 18th, 2026
Our Investment in Twenty: Industrial-Scale Cyber Operations

Twenty is the modern, end-to-end offensive cybersecurity platform for US agencies.

GovCon Wire
Jun 18th, 2026
Cyber warfare startup Twenty raises $100M in Series B funding round.

Cyber warfare startup Twenty raises $100M in Series B funding round. * Twenty has closed a $100 million Series B funding round * Series B has brought Twenty's total funding to $138 million * The Potomac Officers Club's 2026 DOW summits will feature discussions about AI, cyber resilience and more Cybersecurity company Twenty has secured $100 million in a round of Series B financing led by Accel to expand its artificial intelligence-enabled offensive cyber capabilities for the U.S. military and intelligence Community. As investment accelerates across cyber warfare and defense technologies, broader momentum is also building around digital modernization and national security innovation. Two upcoming Potomac Officers Club events will bring together senior leaders to explore these priorities in depth. Register now for the 2026 Air and Space Summit on July 30, followed by the 2026 Navy Summit on Aug. 27, with sessions focused on AI, cyber resilience and digital modernization. The company said Wednesday it has reached a $1 billion valuation with the latest funding round. What are the details of the Series B funding round? Friends & Family Capital, Point72 Ventures and Caffeinated Capital participated in the Series B funding round, which has brought Twenty's total funding to $138 million. Series B builds on earlier financing rounds led by Caffeinated Capital and Tim Junio, co-founder and CEO of Expanse, which was acquired by Palo Alto Networks for $1.25 billion in 2020. Additional early support came from investors, including In-Q-Tel and General Catalyst. What did Twenty CEO joe Lin say about the funding round? Joe Lin, co-founder and CEO of Twenty, said the company is developing AI-enabled capabilities designed to help warfighters disrupt cyberthreats at their origin. "This round is extraordinary validation from some of the world's foremost investors, and we are pouring this funding directly into research and engineering," added Lin. What does Twenty do? Twenty is a venture capital-backed cybersecurity startup focused on building AI-enabled, end-to-end cyber warfare systems for the U.S. and its allies. Established in 2024, the company works to industrialize offensive cyber capabilities by combining AI and automation with controlled deployment, evaluation and mission alignment.

PR Newswire
Nov 20th, 2025
Twenty Raises $38M to Transform Cyber Warfare at Industrial Scale

/PRNewswire/ -- Twenty, the company leading the industrial-scale transformation of cyber warfare technologies, today announced that it has raised $38 million...