Job title: Founding Head of Public SectorLocation: London; 4 days in-office, 1 day wfhReports to: Chief Commercial Officer___________________________________________________________________________Cosine at a glanceCosine is the UK's frontier AI lab for autonomous software engineering — not another coding assistant, but our own models, agent stack, eval harnesses, and product layer.
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 flexability, 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.
The company is at a rare stage: deep technical work, real enterprise pull, and a chance to shape how AI is deployed inside defence, banking, government, and other high-trust environments.
___________________________________________________________________________MissionOwn Cosine’s public sector engagement and GTM motion from founder-led relationship building into a repeatable commercial engine.
The role exists to build on Cosine’s growing reputation across government, defence-adjacent bodies, public sector technology teams, and the wider UK sovereign AI ecosystem, 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 public sector navigation, and part GTM leadership.
___________________________________________________________________________Core responsibilities1.