You will lead the cybersecurity go-to-market strategy for Lumen Sovereign, driving adoption for AI-native red teaming and code review. Working directly with the founders and CCO, you’ll sell to elite security teams at banks, defense organizations, and critical infrastructure providers. This is a high-impact role converting national momentum into a durable commercial motion.
Founding Sales Lead - Cybersecurity and Red Teaming at Cosine.sh
Cosine.sh is Britain’s frontier AI lab, seeking a Founding Sales Lead to own the cybersecurity motion for Lumen Sovereign—the nation’s first sovereign frontier model. Join "The Sovereign AI Lab," where we build specialist models for customer-owned infrastructure and air-gapped environments. You will sell AI-native red teaming and secure code review tools to security teams in banking, defense, and critical infrastructure. If you have a background in technical sales, a founder’s mindset, and a desire to shape the commercial strategy for Britain’s most consequential AI project, Cosine.sh offers the equity and impact you’ve been preparing for.
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Location
London, United Kingdom
Compensation
Not Disclosed + Equity
Company
Cosine
Role overview
Software
Cosine is an autonomous, on-premise coding agent post-trained on human reasoning data to deliver unmatched software-engineering accuracy, security, and speed for regulated enterprises.
What you will do
- Build the end-to-end sales motion for cybersecurity applications, selling directly to CISOs and security teams at major financial and critical infrastructure institutions.
- Establish and manage strategic partnerships with cybersecurity firms to build specialized harnesses and integrations on top of the Lumen Sovereign model.
- Lead high-level technical discovery and negotiations with engineering leaders, managing complex sales cycles without the need for a dedicated solutions architect.
Who this is a fit for
- Possesses a former founder’s DNA or early startup experience, with a proven track record of building technical sales motions from the ground up.
- Demonstrates extensive experience selling deeply technical products such as AI infrastructure, developer tools, or cybersecurity solutions to enterprise-level customers.
- Capable of commanding a room of engineers and executive stakeholders, effectively communicating the depth and security advantages of sovereign AI models.
Why this role is remarkable
- Own the commercial launch of Britain’s first sovereign frontier AI model, targeting high-consequence markets like national defense and global banking.
- Work within a lab that has garnered significant national press and a coalition of partners across telecoms and finance since its London Tech Week debut.
- Secure founding-stage equity in a technically serious team where specialist AI models are already outperforming generalist alternatives in complex engineering domains.
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