Senior / Staff Backend Engineer (+ Equity) at Fast-growing AI FinTech startup

Jack & Jill/External ATS; Greater London; On-site; GBP 80,000 - 100,000; Full time

Job summary

A fast-growing AI FinTech startup in the UK is seeking a Senior / Staff Backend Engineer to build an AI operating system for private capital markets. The role involves designing robust backend services, developing scalable data pipelines, and contributing to the technical vision of the company. Ideal candidates will have over 4 years of experience and expertise in Python, FastAPI, and distributed systems, all within a high-velocity environment.

Qualifications

• 4+ years of software engineering experience at a startup or top-tier tech firm.
• Deep technical expertise in Python and FastAPI.
• Experience with distributed systems and complex product development.

Responsibilities

• Design and implement new capabilities for an autonomous framework.
• Build and maintain scalable data pipelines for complex documents.
• Develop performant APIs and distributed systems for decision-making.

Skills

Python

FastAPI

Postgres

ElasticSearch

Message queues

Job description

Senior / Staff Backend Engineer

Company Description

Fast-growing AI FinTech startup

Job Description

You will join a lean, ambitious team building a category-defining AI operating system for private capital markets. As a senior engineer, you will own features from conception to production, designing robust backend services and agentic frameworks that help top-tier investment firms process complex data and unlock deeper financial insights at scale.

Location

London, UK

Why this role is remarkable

• Work directly with a founding team backed by top-tier VCs and industry executives from leading global investment firms.
• Massive growth trajectory with significant product-market fit and a rapidly expanding international customer base in the US and Europe.
• High-impact opportunity to shape the technical vision of an ultra-growth venture while participating in substantial equity upside.

What you will do

• Design and implement new capabilities for an autonomous agentic framework to achieve human-level analytical expertise.
• Build and maintain scalable data pipelines for ingesting, processing, and indexing large volumes of complex documents.
• Develop performant, streaming-first APIs and distributed systems that power the core platform's decision‑making engine.

The ideal candidate

• 4+ years of software engineering experience at a venture-backed startup or top‑tier technology firm.
• Deep technical expertise in Python, FastAPI, and distributed systems like Postgres, ElasticSearch, and message queues.
• Proven track record of taking complex products from ideation to production in a fast‑paced, high‑velocity environment.