Backend Engineer: Python, FastAPI & Multi-Tenant

Oscar Technology; Greater London; On-site; GBP 85,000 - 105,000; Full time

Job summary

Oscar Technology is seeking a Backend Engineer in London to design and implement multi-tenant data/workflow services as part of a high-growth platform. You’ll integrate Python AI services with a Java/Spring core and own the API layer in a regulated enterprise context.

You’ll report to the UK core team, work primarily in-office at Kings Cross (3 days per week), and collaborate across a dispersed delivery organisation to ship reliable services with strong auditability.

Qualifications

• 5+ years of backend engineering for production SaaS or platforms.
• Experience with multi-tenant systems, isolation, permissions and auditability.
• Strong Python with FastAPI and PostgreSQL, able to work at Java/Spring boundaries.
• Proficient in AWS, Git, CI/CD and Linux.
• Familiar with AI coding tools and evaluating their value in workflows.

Responsibilities

• Design REST and asynchronous services in Python 3.11+ and FastAPI.
• Work at Java/Spring boundaries with PostgreSQL and async SQLAlchemy.
• Implement tenant isolation, context, role-based access and configuration.
• Maintain CI/CD and collaborate with cross-continental teams.

Skills

Python

FastAPI

PostgreSQL

AWS

CI/CD

Linux

AI tools

Education

Engineering degree or equivalent experience

Job description

Oscar Technology is seeking a Backend Engineer in London to design and implement multi-tenant data/workflow services as part of a high-growth platform. You’ll integrate Python AI services with a Java/Spring core and own the API layer in a regulated enterprise context.

You’ll report to the UK core team, work primarily in-office at Kings Cross (3 days per week), and collaborate across a dispersed delivery organisation to ship reliable services with strong auditability.