London, England, United Kingdom · On-site
Job title: Enterprise Account Executive (Defence) Location: London; in-office working as default Start date: ASAP Reports to: Chief Commercial Officer _____________________________________________________________________…
Skills: Enterprise Sales, Defence Procurement, Government Relations, Pipeline Management, Deal Strategy
Sign up with Clera and we'll reach out the moment a role actually fits you — no more spraying applications into the void.
Own and close complex enterprise deals across defence primes, government agencies, and national security organisations. Lead the full sales cycle from outbound sourcing to production deployment while shaping the company's defence go-to-market strategy.
Proven track record of closing enterprise deals within defence or government, specifically selling developer tooling or infrastructure platforms. Requires deep understanding of high-assurance procurement processes and the ability to engage senior technical and security stakeholders.
Job title: Enterprise Account Executive (Defence)
Location: London; in-office working as default
Start date: ASAP
Reports to: Chief Commercial Officer
___
Cosine is a UK sovereign AI model lab that has built 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 makes us unique is our in-house ML research lab that trains LLMs on proprietary software-engineering reasoning data to dramatically increase their coding accuracy. In 2024 this gave us a world-leading score of 72% on OpenAI’s SWE-Lancer benchmark
Cosine is now one of the only available managed products that can be fully air-gapped and deployed on premises, exciting many bulge bracket but extremely risk sensitive and strict enterprises that have rejected all other solutions on the market. We are about to kick off our first live pilots with defence primes and are now scaling our defence go-to-market motion.
As an Enterprise Account Executive for Defence, you will own and close complex enterprise deals across defence primes, government agencies, and national security organisations. You will navigate highly regulated procurement environments and work closely with senior technical, security, and programme stakeholders to turn pilots into long-term production deployments.
This role is ideal for someone who has successfully hunted and closed new logo enterprise deals within defence or government, particularly selling developer tooling, infrastructure, security, or platform technologies into mission-critical engineering teams.
Own the full sales cycle across defence and government accounts, from targeted outbound and partner-led sourcing through to close
Hunt and develop new defence opportunities, including direct relationships with defence primes, government departments, and classified programme teams
Lead complex, multi-stakeholder sales processes involving engineering leadership, security, procurement, and programme owners
Design and manage pilots and technical evaluations, defining success criteria aligned to mission outcomes, security constraints, and operational readiness
Build deal strategies that account for long procurement timelines, framework agreements, and partner ecosystems
Work closely with product, engineering, and leadership to shape Cosine’s defence positioning, deployment models, and roadmap priorities
Help formalise Cosine’s defence go-to-market playbook, including qualification, pilot structures, accreditation pathways, and scale-out strategies
Maintain rigorous pipeline management, forecasting, and CRM hygiene across long-cycle opportunities
A demonstrated track record of closing complex enterprise deals within defence, government, or national security environments
Experience selling developer tooling, infrastructure, security, or data platforms into large, technically sophisticated organisations
Background at, or selling products comparable to, companies such as AWS, Kubernetes, Terraform, GitHub, Datadog, Grafana, Cloudflare, GCP, or similar developer-first or infrastructure platforms
Strong understanding of defence and government procurement processes, including frameworks, primes, and compliance requirements
Credibility engaging with senior technical, security, and programme stakeholders in high-assurance environments
Comfort operating in environments with long sales cycles, multiple decision-makers, and strict security constraints
Strong written and verbal communication skills, with the ability to communicate complex technical concepts clearly to both technical and non-technical audiences
Experience selling on-premise, air-gapped, or classified systems
Familiarity with defence primes, systems integrators, or government procurement frameworks
Exposure to AI, ML platforms, or developer productivity tooling
Existing network within defence, government, or national security technology organisations
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
We are an in-office, high-ownership team. You will work closely with leadership, product, and engineering and play a key role in shaping Cosine’s defence and government GTM strategy. Our current tooling includes Attio, Lemlist, PostHog, Notion, Slack, and Google Workspace, with flexibility to evolve as we scale.
__
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.
Building frontier AI for sovereign environments
Cosine is building frontier model intelligence. Our models have topped public benchmarks for two consecutive years, outperforming OpenAI, Anthropic, Mistral, and DeepSeek. We are also Britain's sovereign AI frontier lab. Selected by the UK government for its £500m Sovereign AI programme, we are the first company to train, own, and deploy a fully sovereign AI model entirely on UK soil with access to the Isambard-AI supercomputer. Cosine can be deployed air-gapped and on-premise for defence, national security, and critical infrastructure, where foreign AI is legally off the table.
Offices: London, E28HD, GB
Building frontier AI for sovereign environments
Cosine is building frontier model intelligence. Our models have topped public benchmarks for two consecutive years, outperforming OpenAI, Anthropic, Mistral, and DeepSeek. We are also Britain's sovereign AI frontier lab. Selected by the UK government for its £500m Sovereign AI programme, we are the first company to train, own, and deploy a fully sovereign AI model entirely on UK soil with access to the Isambard-AI supercomputer. Cosine can be deployed air-gapped and on-premise for defence, national security, and critical infrastructure, where foreign AI is legally off the table.
Offices: London, E28HD, GB
