Backend Engineer

About the role

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.

What you'll work on

- This role is the opportunity to take on the technical leadership on projects, defining and designing systems, making quick proof of concepts and working closely with Product and our Clients.

- Write code and lead others in the team in delivering new service functionality, implementing API’s, data routing/processing and automation mechanisms.

- Development and engineering primarily on the backend services and web application hosted tools and systems of the 9fin platform.

- Taking a leading role within project teams as an IC, running code reviews and mentoring of junior developers, involvement in early research and experimentation with new technologies providing input for new features and products.

- Continually improve on the 9fin codebase taking the chance to automate, refactor and document when you can.

- Variety: Our web platforms are incredibly diverse, from complex financial data modelling, capturing environmental, emission, energy data, incorporation of ML/AI prediction services, data visualisation serving and automation systems.

- Collaboration and teamwork: Cross functional teams are formed for all projects including the appropriate domain expertise from 9fin financial, legal and editorial colleagues. This allows the best quality information and feedback to go directly to engineering project teams. Your ability to explain and break down complex projects to non technical audiences will enable productive and efficient team progress.

- Developer Experience: Through managed automated preview environments, feature flags and well maintained non production environments. You will be able to move with velocity and get feedback and iterate quickly.

Our Backend Stack

- Python is the dominant backend language used

- Flask&FastAPI

- Typing is used within our Python stack to power automated documentation and API definitions

- Relational Databases (PostgreSQL) at the heart of majority of services

- We’re AWS for Cloud hosted services