Senior Security Engineer

About 9fin

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. 9fin replaces this broken infrastructure with a single platform that centralises proprietary credit data, deep analysis, and high-value workflows across global markets.

Today, 9fin powers teams at 300+ blue-chip institutions worldwide, including global banks, asset managers, private equity firms, law firms, and advisors. The business is scaling at exceptional speed, with rapid expansion in the US and best-in-class retention driven by deep workflow adoption.

We’re at a defining inflection point. With proven product-market fit and strong, global market pull, 9fin is accelerating toward becoming the category-defining platform for debt markets worldwide.

We’re looking for a Senior Product Security Engineer to join one of our software engineering teams and help shape the security of our products as we continue to scale.

This role will be embedded within a team responsible for some of the most security‑critical parts of the 9fin platform. The team works on the systems and controls that protect sensitive customer information, ensuring data is stored, accessed and processed securely throughout its lifecycle.

You’ll work alongside product engineers day‑to‑day, participating in planning, design discussions, refinement sessions and technical decision‑making. You’ll help the team make sound architectural decisions about how sensitive information is stored, processed and accessed, balancing security requirements with product and engineering goals.

The team operates at the intersection of application security, cloud security, data protection and AI security. You’ll help shape how 9fin approaches challenges such as tenant isolation, access control, confidential data handling and the secure use of AI systems.

While embedded within product engineering, you’ll remain closely connected to our Platform Engineering and Information Security teams, helping drive a consistent approach to security across 9fin.

This is a hands‑on engineering role. You won’t be building product features full‑time, but you should be comfortable reading, reviewing and writing production code when security requirements demand it.

• 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.

• 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 Postgre
  
  SQL.

• Pragmatic judgement and the ability to balance security, product and engineering needs.

• Ability to influence engineers and stakeholders across multiple teams without relying on formal authority.

• Familiarisation with SOC2 and ISO 42001 is a bonus.

• Security considerations are embedded into product design discussions rather than introduced late in the delivery process.

• Teams can move quickly because secure patterns, architectural guidance and security controls are well understood.

• Risks are identified and addressed before they become incidents.

• Security is seen as an enabler of…