AI Engineer Engineering · Full Time · London

Tracelight Ltd.; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

Tracelight Ltd. in London is building an Excel AI add‑in for complex financial modelling. Join a small, strong engineering team with TS/Rust, in-person at Hoxton office.

You will ship high‑quality code, improve AI harnesses, and own evaluation pipelines while collaborating with a designer to deliver delightful features. We expect top‑centile engineering ability, high agency, and experience with competitive programming or building agents.

Qualifications

• Evidence you are a top centile engineer – no compromises.
• High agency and determination.
• Background in competitive programming, trading, big tech, building agents, TypeScript, Rust, React, devops.

Responsibilities

• Use AI to ship high-quality code as fast as possible. Leverage the latest tools, models and trends.
• Make our AI agent smarter by improving the harness, tools, and optimising context.
• Own evaluation pipelines, data collection, SFT and RL.
• Work with our designer to ensure that every feature feels beautiful and consistent.

Skills

Top centile engineer

High agency

Competitive programming

Trading background

Tools

TypeScript

Rust

React

DevOps

Claude Code

Cursor

Job description

Our mission is to reinvent how businesses make their biggest decisions.

We are starting by building the best Excel AI add-in for complex financial modelling.

Financial models underpin every important decision a company makes. The process of building them today is broken; financial modelling is, by far, the worst-tooled form of programming. Today, Tracelight is Cursor for serious financial modelling in Excel.

Long‑term we will build the AI operating system for the entire strategic decision lifecycle - work that today happens across Excel, PowerPoint, email, and meetings. We believe this new category is one of the most fundamental applications of AI, and a $100bn+ opportunity.

We are a small very strong engineering team, ex Jane Street, Bloomberg, Cambridge, UCL, etc. Tech stack is TypeScript for most things and Rust where it matters. The role is 5 days a week in person in our Hoxton (London) office.

What you will do

• Use AI to ship high‑quality code as fast as possible. Leverage the latest tools, models and trends. AI is no longer optional. You must be amazing at prompting, know different models, and have experience with Claude Code, Cursor, etc. (We are not looking for vibe coders).
• Make our AI agent smarter by improving the harness, tools, and optimising context.
• Own evaluation pipelines, data collection, SFT and RL.
• Work with our incredible designer Joao to ensure that every feature feels beautiful and consistent.
• Over time, become a technical leader and own significant parts of our AI work.

What you will need

Evidence you are a top centile engineer - no compromises on this.

• High agency and determination.
• Any of the following is a plus: background in competitive programming, trading, big tech, building agents, TypeScript, Rust, React, devops