Staff Engineer

9fin

9fin

Software Engineering

London, UK

Posted on Apr 20, 2026

Location

London

Employment Type

Full time

Department

Engineering

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 Staff Engineer to lead the technical vision and architecture for 9fin’s New Markets engineering organisation.

In this role, you’ll define and evolve the system design that underpins our future expansion—owning the end-to-end architecture, setting technical direction, and ensuring our platforms scale effectively as we enter new markets. You’ll create clear technical documentation, align multiple engineering teams around a shared vision, and guide execution by helping teams make thoughtful trade-offs.

This is a high-impact, hands-on leadership role on the IC track. You’ll operate across strategy and execution—partnering with 6+ teams, contributing directly to critical code paths when needed, and raising the engineering bar across the organisation.

What you’ll do

  • Partner with other staff engineers to propose high impact engineering proposals .

  • You will influence technical strategy, participate in technical governance and decision making . You align the technical vision with various stakeholders (primarily the engineering leadership layer) .

  • Design and scale backend services, APIs, and data platforms powering 9fin’s new market products

  • Work on complex entity mapping and data modelling challenges across new market’s data sources

  • Drive database decoupling and system modularisation to improve scalability, flexibility, and long-term maintainability

  • You will review and guide architecture across teams, helping avoid unnecessary coupling and complexity while keeping teams focused on pragmatic, high-impact solutions.

  • Dive into complex legacy systems, identify root causes of friction, and define a clear path to modernisation

  • Deliver high-quality, reliable production code through testing, logging, and alerting

  • Move between deep debugging and high-level system design to shape our platform evolution

  • Set a high bar for engineering through hands-on coding and strong technical leadership.

  • Leverage AI-assisted engineering to accelerate system understanding and delivery

  • Establish best practices, guardrails, and tooling to improve engineering velocity and safety

  • Ensure systems are scalable, reliable, and adaptable as we grow

  • Partner closely with Engineering and Platform

  • You will raise our technical bar by mentoring senior engineers, improving IC hiring and levelling practices, and helping shape how we develop technical talent across 9fin

What we’re looking for

  • Proven track record of building and delivering backend systems from development to production, especially in data intensive environments

  • Deep expertise in distributed systems, APIs, and data pipelines

  • Strong experience with data modelling, entity resolution/mapping, and complex relational domains

  • Familiarity with event-driven architectures, Kubernetes, and cloud-based infrastructure like AWS

  • Experience in database decoupling, service-oriented architectures, or platform modularisation

  • Proficiency in Python (or similar backend languages)

  • Experience modernising legacy systems and improving platform architecture

  • Proven ability to lead complex technical initiatives end-to-end

  • Strong product and customer mindset

  • Comfortable operating in ambiguity and driving clarity

  • Skilled at balancing hands-on technical work with guiding and aligning others

  • Communicate clearly and effectively with technical and non-technical audiences.

Nice to have:

  • Experience as a founding engineer or CTO at a startup, or building systems from scratch in early-stage environments

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)

  • Hybrid working model, to allow you the flexibility to decide how, where and when you do your best work

  • 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

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.