Senior Product Security Engineer

4w1 month ago

9fin

London, GB · Full-time · £90,000 – £130,000

About this role

9fin is the AI platform powering global debt markets, the world’s largest asset class at over $145 trillion. Debt markets are vast, global, and mission-critical, yet still run on fragmented data, PDFs, and manual workflows, and 9fin replaces this broken infrastructure with a single platform that centralises proprietary credit data, deep analysis, and high-value workflows.

As a Senior Product Security Engineer, you will be embedded within a product engineering team responsible for some of the most security-critical parts of the 9fin platform. Day-to-day, you'll work alongside product engineers in planning, design discussions, refinement sessions, and technical decision-making to ensure security is considered from the outset.

This role operates at the intersection of application security, cloud security, data protection, and AI security. The team works on the systems and controls that protect sensitive customer information, ensuring data is stored, accessed, and processed securely throughout its lifecycle, while remaining closely connected to Platform Engineering and Information Security teams.

9fin is at a defining inflection point with proven product-market fit and strong global market pull, accelerating toward becoming the category-defining platform for debt markets worldwide. You'll help shape how 9fin approaches challenges such as tenant isolation, access control, confidential data handling, and the secure use of AI systems.

Requirements

Significant experience securing modern software systems and applications.
Strong understanding of secure software architecture, threat modelling, and security engineering practices.
Deep familiarity with cloud-native architectures and security controls, particularly within AWS.
Experience designing systems that handle sensitive, confidential, or regulated data.
Comfortable reading, reviewing, and writing production code, ideally with experience in Python or similar backend technologies.
Familiar with the security considerations of modern data stores such as PostgreSQL.
Pragmatic judgement and the ability to balance security requirements with product and engineering goals.

Responsibilities

Embed within a product engineering team and help shape the security of our products from design through to production.
Influence architecture, design, and implementation decisions to ensure security is considered from the outset.
Partner with Product Engineering, Platform Engineering, and Information Security teams to identify risks, define appropriate controls, and build secure-by-default systems.
Contribute code, reviews, and technical guidance where security expertise is required.
Act as a security advocate and trusted advisor within the team, helping balance risk, usability, and delivery.
Help the team make sound architectural decisions about how sensitive information is stored, processed, and accessed.

Benefits

Work at the intersection of application security, cloud security, data protection, and AI security.
Join a company at a defining inflection point with proven product-market fit and rapid US expansion.
Be part of a team that powers 300+ blue-chip institutions worldwide, including global banks and asset managers.
Embedded role within a product engineering team with close connection to Platform Engineering and InfoSec.