---
title: 'Senior Backend Engineer at 9fin'
canonical: 'https://feeny.ai/job/senior-backend-engineer-9fin-london-45nvkmyass68'
type: 'job'
last_seen: '2026-10-18'
---

# Senior Backend Engineer at 9fin

- **Company:** 9fin
- **Location:** London, United Kingdom
- **Employment:** full-time
- **Posted:** 2026-09-28
- **Last confirmed live:** 2026-10-18
- **Apply:** https://jobs.ashbyhq.com/9fin/06038f70-eddf-4b6b-8fa9-5dbf34e237d0

## Job description

## 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

The team maintains a strong focus on impact, using technology to deliver value for the business. While we have a high-level vision from the business, we have autonomy to set our team goals and define our own success. We take responsibility for our outcomes and emphasize proactive behaviours like ownership and accountability.

- As part of a cross functional team, lead projects by defining and designing systems, building proof of concepts, and delivering new service functionality - including APIs, data processing and automation - while collaborating with Product and Clients
- Development and engineering primarily on the backend services and web application hosted tools and systems of the 9fin platform.
- Play an impactful role within project teams as a senior IC, running code reviews, mentoring other developers, leadership & involvement in early research and experimentation with new technologies providing input for new features and products.
- Continually improve the 9fin codebase taking the chance to automate, refactor and document when it’s most impactful..
- Very diverse web platforms, from complex financial data modelling, complex access control business logic, 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 have our own internal developer platform with standardised paved road approaches to infrastructure to bring your code into production as quickly as possible.
- We’re AWS for Cloud hosted services
- Heavy use of AWS lambda Serverless
- Docker (AWS ECS) for uniform development/deployment from dev to prod

## Requirements

This role will be a great fit if you:

- Have experience operating as a Senior IC Engineer, leading systems design and infrastructure discussions, mentoring more junior team members, and scoping work within cross-functional product teams.
- Plan and reason about software effectively, clearly and compellingly communicating its purpose within systems and its business impact on clients
- Have hands-on experience designing data flow through software, from persistent storage to API endpoints, while applying industry best practices for validation
- Experience with Python and its web frameworks (we currently use FastAPI with strong typing & Pydantic)
- Strong experience delivering APIs, Service Oriented Architecture
- Strong working knowledge of SQL statements for retrieving data
- A good collaborator and communicator with cross functional engineering teammates and others within 9fin
- Code Quality: Through writing testable, maintainable code, and by engaging in code review for your own work and for reviewing others

Nice-to-have:

- Experience in data modelling and with a pipeline orchestrator

## Benefits

We’re a scaling start up and we enjoy sharing our success, when the company succeeds, we always reinvest that in our people. We also offer huge amounts of responsibility, an abundance of opportunity for growth and a platform to truly excel. Financial & Insurance

- Competitive Salary (our salary bands are benchmarked at the top end of the market)
- Equity options
- Pension (your minimum contributions are 4% with 9fin matching up to 7%)
- Private Medical Insurance
- Paid sick leave with Income Protection for long periods of illness
- Group Life Assurance
- Season Ticket Loan & Cycle to Work schemes

Time off

- 25 holiday days per year
- Local public holidays (with the ability to exchange them for alternative days)
- Work abroad for up to 3 months a year
- 1 month paid sabbatical after 5 years of service
- Enhanced parental leave & flexible working arrangements available

Training & Culture

- Professional learning and development budget
- Quarterly team socials
- Summer and Winter company social events

Location 9fin is a hybrid company, and the office is a regular part of how we work. From January 2027, all employees will work from their designated 9fin office on Tuesdays and Wednesdays. Some teams may be asked to be in the office more often, where the nature of their work calls for it. For the rest of the week, you may work from wherever works best for you and your team 9fin is an equal opportunities employer At 9fin we are dedicated to building and promoting a fair and inclusive workplace where everyone can reach their full potential and truly belong. We recognize that building diverse teams enables a more creative and productive environment. If you’re excited about this role but your experience doesn’t perfectly align with the job description, we encourage you to apply anyway. You might just be who we’re looking for — either for this role, or perhaps another.

## About 9fin

## Company Overview
- **One-liner**: 9fin is the AI-native intelligence platform that provides data, analytics, news, and AI-powered workflows for global debt capital markets.
- **Entity Type**: Private (Series C)
- **Headquarters**: London, United Kingdom
- **Founded**: 2016
- **Founders**: Steven Hunter (CEO) and Hussam El-Sheikh (CTO)

## Core Business
- **Primary industry/industries**: Financial Technology (Fintech), Debt Capital Markets, AI/Data Analytics
- **Target customers**: B2B, specifically investment banks, asset managers, hedge funds, law firms, private credit funds, and advisory firms.
- **Mission or purpose statement**: To become the number one platform for debt markets globally, redefining how debt markets are understood and acted on by credit teams.

## Products & Services
- **9fin Platform**: A unified platform combining breaking news from expert reporters, structured data and analytics, and AI-powered workflows. It covers leveraged finance, distressed debt, CLOs, private credit, ABF, and investment grade across North America, Europe, Latin America, and Asia-Pacific.
- **9fin AI (AI Chat & Research Grid)**: Launched in June 2026, these tools help credit professionals move from question to conviction faster. AI Chat provides cited answers to complex credit questions in seconds. Research Grid enables users to build structured company comparisons in minutes using pre-defined or custom questions. Every output is grounded in proprietary debt market data and linked to source material. [9fin.com](https://www.9fin.com/)

## Market Standing
- **Valuation/Market Cap**: $1.3 billion (as of Series C fundraise in March 2026) [cbinsights.com](https://www.cbinsights.com/company/9fin)
- **Key Metric**: Total funding raised to date: $253.95M [cbinsights.com](https://www.cbinsights.com/company/9fin)
- **Notable Investors/Partners**: Not all investors are publicly listed, but the company has raised over $250M across Series A, B, and C rounds.
- **Growth Signals**: 
    - In June 2026, launched two major AI tools (AI Chat and Research Grid) [prnewswire.co.uk](https://www.prnewswire.co.uk/news-releases/9fin-launches-next-generation-of-ai-tools-for-debt-capital-markets-302794326.html)
    - Powers credit teams at 300+ leading global institutions [9fin.com](https://www.9fin.com/about)
    - Employs 350+ people globally [9fin.com](https://www.9fin.com/about)
    - Scaled globally with offices in London, New York, Hong Kong, and Belfast [9fin.com](https://www.9fin.com/about)

## Competitive Advantages
- **AI-native foundation**: Built from the ground up with a decade of proprietary debt market data powering its AI, creating a strong moat. [9fin.com](https://www.9fin.com/about)
- **Deep domain expertise**: Co-founders have backgrounds in investment banking (J.P. Morgan) and engineering (Deutsche Bank), and the platform is calibrated by in-house credit, distressed, and legal analysts with decades of experience. [9fin.com](https://www.9fin.com/about)
- **Comprehensive data**: Unifies public, private, and distressed credit data in a single connected view, replacing multiple legacy tools. [9fin.com](https://www.9fin.com/)
- **Trusted by the market**: Used by 80% of trading desks among top-tier institutions. [9fin.com](https://www.9fin.com/)

## Strategic Focus
- **Current priorities and direction for growth**: Scaling globally and deepening the AI platform. The company is building "credit-specific AI agents that proactively monitor, draft and alert," moving from a source of intelligence to the platform where credit professionals get work done. [prnewswire.co.uk](https://www.prnewswire.co.uk/news-releases/9fin-launches-next-generation-of-ai-tools-for-debt-capital-markets-302794326.html)

## Why Work Here
- **Culture highlights**: Emphasizes "true flexibility," "a culture of care," and the opportunity to "build at the edge" with the latest AI tools. The company values ambition and offers real opportunities to make an impact. [9fin.com](https://www.9fin.com/careers)
- **Remote/hybrid/office policy**: Offers a flexible work model: "Work from home, or from one of our great offices around the world. We encourage time with your team, while giving you the flexibility when you need it." [9fin.com](https://www.9fin.com/careers)
- **Notable perks or engineering culture**: 
    - Enhanced parental leave, flexible hours, and sabbaticals. [9fin.com](https://www.9fin.com/careers)
    - Engineers, product, and AI teams own the full experience, from data architecture to interface, working closely with customers. [9fin.com](https://www.9fin.com/careers)
    - High growth trajectory with global scaling, providing real career advancement opportunities. [9fin.com](https://www.9fin.com/careers)

## Sources
1. [9fin Careers Page](https://www.9fin.com/careers)
2. [9fin About Page](https://www.9fin.com/about)
3. [9fin Homepage](https://www.9fin.com/)
4. [CB Insights Company Profile](https://www.cbinsights.com/company/9fin)
5. [PRNewswire - 9fin Launches Next Generation AI Tools](https://www.prnewswire.co.uk/news-releases/9fin-launches-next-generation-of-ai-tools-for-debt-capital-markets-302794326.html)
6. [9fin Jobs Portal (Ashby)](https://jobs.ashbyhq.com/9fin)

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