Senior Fullstack Engineer — AI-Driven FinTech Platform

Dex; Greater London; On-site; GBP 90,000 - 140,000; Full time

Job summary

Dex is partnering with a trusted client to recruit a Senior Fullstack Engineer. You will own core product surfaces end-to-end, from architecture to production, and build workflows on internal AI infrastructure that integrate with the tools finance teams rely on.

You will work with Python (FastAPI), TypeScript, React, and PostgreSQL, delivering user-facing experiences tightly coupled to our AI backbone. This role emphasizes craft, performance, and a keen interest in enterprise finance workflows.

Qualifications

• 4+ years building and shipping production software at a venture-backed startup or top-tier tech company.
• Strong fullstack fluency across Python (FastAPI), TypeScript, React, and PostgreSQL.
• Experience building user-facing products tightly coupled to LLMs and autonomous agents.
• An appetite for deep problem domains and a high bar for craft when building for demanding finance professionals.

Responsibilities

• Own core product surfaces across the entire stack using Python, FastAPI, TypeScript, React, and Postgres, from architecture to post-launch telemetry.
• Build complex user workflows directly on top of internal AI infrastructure, including streaming agent execution, end-to-end citations, and resumable code environments.
• Design interfaces and authoring experiences that integrate deeply into the daily tools investment teams live in, such as spreadsheets, presentations, and email.
• Uphold code quality, system performance, and architectural decisions that help a fast-moving engineering team sustain high shipping velocity.

Skills

Fullstack development

LLMs and autonomous agents

Finance domain familiarity

Production software delivery

Tools

Python

FastAPI

TypeScript

React

PostgreSQL

Job description

Dex is partnering with a trusted client to recruit a Senior Fullstack Engineer. You will own core product surfaces end-to-end, from architecture to production, and build workflows on internal AI infrastructure that integrate with the tools finance teams rely on.

You will work with Python (FastAPI), TypeScript, React, and PostgreSQL, delivering user-facing experiences tightly coupled to our AI backbone. This role emphasizes craft, performance, and a keen interest in enterprise finance workflows.