Senior Backend Engineer

About the role

You will operate as a senior backend engineer within a focused cross functional team owning the design, delivery, and operation of core platform capabilities on the 9fin debt markets AI platform. You will lead projects that define and design new systems, build proof of concepts, and ship production ready service functionality including APIs, data processing pipelines, and automation directly impacting global financial institutions. The role requires you to take full responsibility for outcomes, exercise proactive ownership and accountability, and communicate complex technical and business tradeoffs clearly to both engineering peers and non technical stakeholders. You will work on very diverse web platforms spanning complex financial data modelling, intricate access control business logic, incorporation of ML and AI prediction services, and data visualisation serving, all aimed at replacing brittle manual workflows with robust automated infrastructure.

Key facts

What you'll do

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.

Operate primarily on the backend services and web application hosted tools and systems of the 9fin platform using Python as the dominant backend language.

Play an impactful role within project teams as a senior IC, running code reviews, mentoring other developers, providing leadership, and driving early research and experimentation with new technologies to inform new features and products.

Continually improve the 9fin codebase by automating repetitive tasks, refactoring legacy components, and documenting critical parts of the system when it is most impactful to reliability and developer velocity.

Work across very diverse web platforms involving complex financial data modelling, sophisticated access control business logic, capturing environmental, emission, and energy data, integration of ML and AI prediction services, and data visualisation serving alongside automation systems.

Collaborate in cross functional teams that include domain experts from 9fin financial, legal, and editorial functions, ensuring the highest quality information is surfaced to engineering project teams and that complex projects are broken down for non technical audiences.

Enhance developer experience by leveraging managed automated preview environments, feature flags, and well maintained non production environments to move with velocity, obtain rapid feedback, and iterate on solutions quickly.

Design and deliver robust APIs and services using Flask and FastAPI, embracing strong typing in Python to power automated documentation and API definitions while maintaining high standards of reliability and performance.

Own data flow design from persistent storage through to API endpoints, applying industry best practices for validation, security, and operational monitoring across PostgreSQL backed services and serverless workloads.

Operate within an AWS environment with heavy use of AWS Lambda for serverless compute and Docker via AWS ECS to ensure uniform development and deployment from development through to production.

Requirements

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 at the 9fin platform.

Plan and reason about software effectively, clearly, and compellingly communicating its purpose within systems and its business impact on clients served by the 9fin debt markets AI platform.

Possess hands on experience designing data flow through software, from persistent storage to API endpoints, while consistently applying industry best practices for validation, testing, and maintainability.

Demonstrate strong experience with Python and its web frameworks, particularly FastAPI, with an emphasis on typing and the use of Pydantic for robust data validation and automated documentation.

Bring strong experience delivering APIs and working within a Service Oriented Architecture across distributed systems that power global financial workflows.

Maintain a strong working knowledge of SQL statements for retrieving, transforming, and optimising data within relational databases, especially PostgreSQL.

Be a collaborative communicator who works effectively with cross functional engineering teammates and with colleagues in financial, legal, and editorial roles across 9fin offices.

Write code with quality and rigor, focusing on testable, maintainable implementations and actively engaging in code review for both your own work and the work of others to uphold high standards across the codebase.

Nice to have

Experience in data modelling and working with a pipeline orchestrator to manage complex data workflows and dependencies.

Practical notes

This role is based in London and is a full time engagement.