Senior Full-Stack Engineer: TS/Python, AI-Driven Fintech

Oscar Technology; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

Oscar Technology is seeking a Full Stack Engineer for a central London role with three days on-site. You will own the full stack from database to UI, designing data-heavy interfaces in TypeScript/React and building scalable Python services with multi-tenant PostgreSQL schemas.

You’ll work closely with senior leadership in a small, high-ownership London team, shipping AI-enabled features and ensuring security, auditability, and regulatory compliance. A competitive package is on offer.

Qualifications

• 5+ years of software engineering with real full-stack ownership in production.
• Strong TypeScript, React, Python and PostgreSQL.
• Auth and access control experience in a multi-tenant B2B product.
• AWS (or similar), CI/CD and containers.
• A track record of setting technical direction and leading architecture decisions.
• Daily use of AI coding tools (Cursor, Claude Code or similar) and a considered view on where they help.

Responsibilities

• Build data-heavy, accessible interfaces in TypeScript and React with RBAC.
• Design services and REST APIs in Python (FastAPI/Django) with OpenAPI contracts.
• Model data in PostgreSQL: schema design, migrations, indexing and multi-tenant isolation.
• Build event-driven and background processing, plus real-time features over WebSockets.
• Implement SSO, OTP and session/JWT auth, integrating with Microsoft 365 and CRMs.
• Collaborate with AI/ML team to ship LLM-powered features with auditable UX.
• Deploy, operate on AWS with CI/CD, observability and SOC 2 / UK GDPR awareness.

Skills

TypeScript

React

Python

PostgreSQL

Multi-tenant architecture

CI/CD

AWS

Education

Bachelor's degree in engineering or computer science

Tools

AWS

Docker

Kubernetes

OpenAPI

Job description

Oscar Technology is seeking a Full Stack Engineer for a central London role with three days on-site. You will own the full stack from database to UI, designing data-heavy interfaces in TypeScript/React and building scalable Python services with multi-tenant PostgreSQL schemas.

You’ll work closely with senior leadership in a small, high-ownership London team, shipping AI-enabled features and ensuring security, auditability, and regulatory compliance. A competitive package is on offer.