Senior Information Security Officer Equity at Definely

Job Title

Senior Information Security Officer

£65k-£85k + Equity

Definely is a Series B Legal Tech company backed by Microsoft, Google, and Octopus Ventures. Founded by former Freshfields lawyers, they build AI-powered contract review tools used by over 150 elite firms globally, including Magic Circle leaders like A&O Shearman and Slaughter and May, to streamline complex legal workflows.

As Senior Information Security Officer at Definely, you will own the company’s security posture and compliance programs. You’ll lead ISO 27001 and SOC 2 audits, manage risk assessments, and secure AI-driven product features. This pivotal role combines governance with hands‑on IT operations to safeguard sensitive data for world‑leading legal enterprises.

London, UK

• Shape the security strategy for a high‑growth Legal Tech company recently backed by a Series B funding round from Microsoft, Google, and Octopus Ventures.
• Impact global legal giants like Samsung and IKEA by ensuring the security of AI‑driven tools used for critical contract negotiations.
• Enjoy a high‑impact, hybrid role that blends strategic governance with tactical IT operations, offering direct influence over the company’s scaling security infrastructure.

• Own and evolve Definely’s Information Security Management System (ISMS), leading readiness for ISO 27001, SOC 2 Type II, and ISO/IEC 42001 certifications.
• Embed secure SDLC practices and perform threat modelling for AI/LLM‑enabled products, working closely with engineering to safeguard product design.
• Manage day‑to‑day IT operations, including device management and onboarding, while leading company‑wide incident response plans and vendor security reviews.

• Proven experience managing ISO 27001 and SOC 2 certifications within a SaaS or product‑led environment, ideally using compliance automation tools like Drata.
• Technical expertise in cloud security (Azure or AWS), identity management (SSO/IAM), and securing AI‑based systems.
• Strong background in both security governance and hands‑on IT support, with relevant certifications such as CISSP, CISM, or ISO 27001 Lead Auditor.