Mid/Senior Software Engineer

Jack and Jill AI; Greater London; On-site; GBP 65,000 - 85,000; Full time

Job summary

A leading fintech startup in London is looking for a Mid/Senior Software Engineer to drive end-to-end feature development. This role involves building and scaling core product features within a high-energy environment focused on AI-driven automation. The ideal candidate has over 5 years of experience with React and TypeScript and is eager to collaborate with founders to influence product architecture. Join a team transforming workflows for global investment funds and enjoy substantial ownership of the development process.

Qualifications

• 5+ years of professional experience in React and TypeScript ecosystems.
• Proven ability to lead features from data modeling to front-end experiences.
• Curiosity for AI automation and experience with modern code-assist tools.

Responsibilities

• Build and scale core product features across the full stack.
• Collaborate with founders to define product direction.
• Design AI-driven systems for financial workflows and reporting.

Skills

React

TypeScript

Node

AWS

Postgres

AI automation

Tools

Cursor

Copilot

Job description

Mid/Senior Software Engineer

Company Description: VC-backed fintech SaaS

Location: London, UK

Job Description: You will join an agile team building intelligent tools for private equity and debt investors. You'll own end-to-end feature development across a React and Node stack, replacing manual workflows with automated systems. This role offers significant ownership in shaping the architecture of a platform already trusted by funds managing billions in capital.

Why this role is remarkable:

• Ship high-impact features from 0→1, including AI agents and event-driven automation for global investment funds.
• Join a well-funded startup backed by top-tier VCs at a stage where you can influence the core architecture.
• Work in an elite, high-energy environment that prioritizes speed, product-minded engineering, and collaborative in-person problem-solving.

What you will do:

• Build and scale core product features across the full stack using React, TypeScript, Node, and AWS infrastructure.
• Collaborate directly with founders to define product direction and navigate complex technical trade-offs.
• Design and implement multi-tenant AI-driven systems to automate sophisticated financial workflows and reporting.

The ideal candidate:

• Professional experience building production web applications with 5+ years in React and TypeScript ecosystems.
• Proven ability to own features end-to-end, from data modeling in Postgres to polishing front-end user experiences.
• High curiosity for AI automation and experience utilizing modern code-assist tools like Cursor or Copilot to accelerate development.

Next steps:

1. Visit our website.
2. Click 'Talk to Jack'.
3. Talk to Jack to explain your experience and ambitions.
4. Jack will ensure Jill considers you for the role.
5. If Jill thinks you’re a great fit and her client wants to meet you, they will make introductions.
6. Otherwise, Jack will find you excellent alternatives.