Back End Developer (Python + FastAPI)

Harnham; Greater London; Hybrid; GBP 72,000 - 88,000; Full time

Benefits offered by this job

Hybrid work

Benefits

Growth opportunity

Job summary

Harnham is building a next-generation AI platform for the investment and financial services sector. You will join a founding-style engineering team to shape product and technical direction at an early stage.

Responsibilities include designing and building backend services in Python, developing scalable APIs, and working with cloud infrastructure to deploy AI features. Hybrid work available with King's Cross base.

Qualifications

• Experience with FastAPI, Django or similar frameworks.
• Experience building SaaS or B2B products.
• Exposure to AWS or other cloud environments.
• Understanding of scalable system design and modern development practices.

Responsibilities

• Design, build and maintain backend services using Python.
• Develop scalable APIs and integrations.
• Work with cloud infrastructure and deployment pipelines.
• Support the development of AI and LLM-powered functionality.
• Write clean, secure and maintainable code.

Skills

Python

Backend

APIs

Cloud

Tools

FastAPI

Django

AWS

Job description

We're working with an AI software company building a next-generation platform for the investment and financial services sector.

This is a unique opportunity to join a founding-style engineering team, helping shape both the product and technical direction from an early stage. Whilst the environment feels like a startup, the business benefits from the backing, investment and stability of an established parent company.

The Role You'll be responsible for building the systems that power the platform, from APIs and integrations through to cloud infrastructure and AI services. Working closely with Product, Data and Engineering teams, you'll help design and scale a platform that supports complex workflows and AI-powered functionality.

Key Responsibilities

• Design, build and maintain backend services using Python
• Develop scalable APIs and integrations
• Work with cloud infrastructure and deployment pipelines
• Support the development of AI and LLM-powered functionality
• Write clean, secure and maintainable code

Ideal Background

• Experience with FastAPI, Django or similar frameworks
• Experience building SaaS or B2B products
• Exposure to AWS or other cloud environments
• Understanding of scalable system design and modern development practices

Package

• Up to £80,000 + Benefits
• Hybrid working (3 days per week in King's Cross)
• Opportunity to join a growing AI business at a key stage of its journey