Software Engineer

Understanding Recruitment; England; On-site; GBP 90,000 - 130,000; Full time

Job summary

Understanding Recruitment partners with a highly ambitious AI startup reinventing how businesses make major decisions. They are building the best AI add-in for complex financial modelling in Excel and are seeking exceptional engineers to join a small, elite team.

You’ll own features across the stack, leveraging AI tooling to ship fast and push the technical direction as the product scales in a high-growth environment.

Qualifications

• Evidence of being a top‑centile engineer.
• Exceptional problem‑solving ability and strong software engineering fundamentals.
• High agency, determination and ownership mindset.
• Ability to move quickly, learn new technologies and wear multiple hats.
• Strong interest in AI and experience using modern AI tooling.
• Ability to work across the stack and not be confined to one area.
• Genuine passion for building great products, not just writing code.
• Rust (open to low-level languages e.g. C++).
• TypeScript
• React
• AI/LLM tooling
• Backend infrastructure & DevOps
• Competitive programming experience (e.g. Olympiads)
• Trading or financial technology background
• Experience building AI agents

Responsibilities

• Owning features end-to-end – from Rust services and backend to the frontend.
• Using the latest AI tools and models to ship high-quality software rapidly.
• Building and improving AI agents, including their harness, tools and context optimisation.
• Writing highly performant software with optimisations and reduced allocations.
• Owning and improving backend infrastructure and CI pipelines.
• Debugging low-level issues and continuously optimising system performance.
• Collaborating with design to ensure polished, beautiful and consistent features.
• Taking increasing technical ownership as the product scales.

Tools

CI/CD pipelines

Backend services

Job description

Do you have a track record of building exceptional software and want to work on a genuinely ambitious AI product?

Are you excited by high ownership, cutting-edge AI tooling, deep technical challenges, and the opportunity to become a technical leader within a small, elite engineering team?

Software Engineer – AI x Financial Modelling

Will relocate and sponsor

Experience: Exceptional engineers – high agency and strong technical fundamentals

I’m excited to be working with a very ambitious AI startup reinventing how businesses make some of their biggest decisions. They’re starting by building the best AI add-in for complex financial modelling in Excel – essentially Cursor for financial modelling.

Financial models sit underneath huge decisions across M&A, private equity, investment, corporate strategy and consulting, yet the tooling behind them remains incredibly manual and outdated.

They’re building something fundamentally different.

Long-term, their ambition is to create an AI operating system for the entire strategic decision lifecycle – spanning Excel, PowerPoint, email and meetings. They’re tackling a potentially enormous new category at the intersection of AI, software engineering and financial decision‑making.

They’re now looking for exceptional Software Engineers to join a small, extremely high‑calibre engineering team and help build the product from the ground up.

You’ll work directly on:

• Owning features end-to-end – from Rust services and backend infrastructure through to the frontend
• Using the latest AI tools and models to ship high-quality software at exceptional speed
• Building and improving AI agents, including their harness, tools and context optimisation
• Writing highly performant software – removing allocations, optimising queries and caching aggressively
• Owning and improving backend infrastructure and CI pipelines
• Debugging low-level issues and continuously optimising system performance
• Working closely with design to ensure every feature feels polished, beautiful and consistent
• Taking increasing technical ownership as the company and product scale

They’re particularly interested in engineers who have:

• Evidence of being a top‑centile engineer
• Exceptional problem‑solving ability and strong software engineering fundamentals
• High agency, determination and a genuine desire to take ownership
• The ability to move quickly, learn new technologies and wear multiple hats
• A strong interest in AI and experience using modern AI coding tools effectively
• The ability to work across the stack rather than being restricted to one area
• A genuine passion for building great products, not simply writing code
• Rust (but they are open to any low-level language e.g. C++)
• TypeScript
• React
• AI / LLM tooling
• Backend infrastructure & DevOps
• Competitive programming experience e.g. Olympiads or Programming Contests
• Trading or financial technology background
• Experience building AI agents

What they’re looking for:

• High agency – you see a problem and take ownership of solving it
• Technical excellence – you care about performance, architecture and writing exceptional software
• AI-native mindset – you understand that AI is now an essential part of the engineering workflow
• Speed + quality – you can leverage AI to move incredibly quickly without becoming a “vibe coder”
• Curiosity – you enjoy getting into unfamiliar areas and figuring things out
• Product mindset – you care about how the software feels, not just whether it works
• Leadership potential – over time, you’ll have the opportunity to own significant parts of the product
• Join a small, exceptionally strong engineering team with backgrounds including Cambridge and UCL, Jane Street and Bloomberg
• Work on a genuinely ambitious AI product tackling a huge, under‑served problem
• Own features across the entire stack rather than being confined to one area
• Work at the cutting edge of AI-native software development
• Have significant influence over the technical direction and product
• Opportunity to become a technical leader and own major parts of the product as the company scales
• Build something from the ground up in a highly ambitious environment
• Work closely with an exceptional designer and engineering team to create a product that is both technically excellent and beautiful

If you’re an exceptional engineer who wants to work at the intersection of AI, financial modelling and high-performance software, with the opportunity to have genuine ownership and impact from day one, this is a seriously exciting opportunity.