Founding Head of Telco in London

Location: London; 4 days in-office, 1 day wfh

Reports to: Chief Commercial Officer

Cosine is the UK's frontier AI lab for autonomous software engineering. We build our agent tooling entirely in-house and post-train open-source models to deliver reliable, enterprise-grade coding performance in security-critical settings. Our offerings can be used as SaaS, deployed on VPC, on-prem or fully air-gapped. Through this flexibility, we are able to service large-scale, highly regulated enterprises and industries including defence, financial service and healthcare. We're backed by YC and were recently selected for the UK's sovereign AI programme.

Mission: Own Cosine's telco engagement and GTM motion from founder-led relationship building into a repeatable commercial engine. The role exists to build on Cosine's existing sovereign AI momentum with telecoms, critical national infrastructure operators, and strategic technology partners, turning senior interest into deep institutional relationships, clearly understood priorities, and qualified commercial opportunities.

This is a critical sector-building role: part enterprise sales, part partnerships, part market development, part infrastructure strategy, and part GTM leadership.

Core responsibilities:

• Lead engagement with telco operators: Own Cosine's day-to-day engagement with priority telco organisations, including national telecoms operators, managed service providers, network infrastructure providers, and telecoms technology teams.
• Build multi-threaded senior relationships: Develop relationships across multiple divisions, business units, and seniority levels in each target account.
• Build Cosine's understanding of telco sovereign AI priorities: Run structured discovery across telco organisations to understand what they truly care about in sovereign AI, AI coding, and enterprise automation.
• Build towards commercial opportunities: Convert relationship-building, technical education, and market development into qualified pipeline opportunities.
• Work closely with partnerships on telco ecosystem routes: Build and manage relationships with the partners that matter in telco.
• Navigate telco routes to market: Build a clear view of the commercial and technical routes that matter for Cosine in telco.
• Help build the GTM team in telco: Define what the telco GTM motion should become as Cosine scales.

What good looks like in the first 6 months:

• Multi-threaded relationships established across the most important telco accounts.
• A structured view of telco sovereign AI use cases, buyer priorities, objections, deployment models, partner routes, and buying triggers.
• Qualified opportunities progressing into discovery, technical deep-dives, pilots, partner motions, deployment planning, or commercial proposals.
• Clear working rhythm with the Head of Partnerships on telco ecosystem partners.
• A clear telco GTM playbook that future hires can build from.

Success metrics:

• Number of priority telco accounts actively engaged.
• Number of senior stakeholder relationships built across target accounts.
• Quality of customer insight captured on sovereign AI priorities, infrastructure requirements, deployment constraints, and use cases.
• Qualified telco opportunities created.
• Evidence that Cosine is becoming a serious strategic partner in target telco accounts.

Candidate profile:

• Has sold, partnered, or built relationships inside telecoms, cloud infrastructure, managed services, critical national infrastructure, or enterprise technology providers.
• Understands how telcos buy, partner, and productise new technology.
• Can credibly engage senior stakeholders while still doing the account-by-account follow-up work themselves.
• Is comfortable working with SIs, infrastructure providers, and technology partners without losing sight of Cosine's own commercial interest.
• Thinks commercially, writes clearly, and can build account plans, briefing notes, proposals, partner materials, and internal decision papers without heavy supervision.

Summary: The Founding Head of Telco should make Cosine impossible to ignore for the right telecoms and infrastructure organisations. They should build on Cosine's sovereign AI momentum, understand what telcos actually need from AI, build the relationships required to be taken seriously, and work closely with the Head of Partnerships to create credible routes through SIs, cloud partners, infrastructure providers, and telco technology ecosystems.

Why join Cosine:

• Opportunity to sell a genuinely differentiated product into mission-critical defence and national security environments.
• Meaningful early equity with real upside.
• Direct impact on product direction and go-to-market strategy.
• Small, elite team with high standards and strong technical depth.

Equal Opportunity: We're an equal opportunity employer. We value diverse backgrounds and encourage applications from everyone who meets the role requirements, even if you don't tick every box.