Software Engineer (up to £300k)

Dex; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Dex is seeking a senior engineer to join a small, high-caliber team in Hoxton, London, to build an AI-enabled coding assistant and power a new AI operating system for strategic decisions. You will own features end-to-end—from Rust services to backend and frontend—shipping high-quality code with the latest AI tools.

Expect deep technical challenges, performance optimization, and infrastructure improvements as you work in person five days a week at our Hoxton office.

Qualifications

• Proven track record delivering features end-to-end across the stack.
• Experience with Rust, TypeScript and React in production systems.
• Strong emphasis on performance optimization and scalable infrastructure.

Responsibilities

• Ship high-quality code using AI tooling and models.
• Own features end-to-end from Rust services to backend and frontend.
• Optimize for performance, including query tuning and CI improvements.
• Refine AI agent harness, tools and context to improve intelligence.

Skills

Top-tier engineer

AI for coding

End-to-end ownership

Performance optimization

Rust

TypeScript

React

Backend development

Frontend development

Tools

Claude Code

Cursor

Job description

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process. Dex is an AI recruiter agent that helps you run your job search. Tell Dex your stack, seniority, and what you want to build. We will manage your applications and surface other opportunities that are a fit.

The role

This company is reinventing how businesses make their biggest decisions. They're starting by building the best AI add-in for complex financial modelling in Excel. Financial models underpin every critical business decision, yet the tooling for this form of programming is fundamentally broken. This is a chance to fix it. The long-term vision is an AI operating system for the entire strategic decision lifecycle, a new category with a massive market opportunity. The engineering team is small, but comprises top-tier talent from leading institutions. You will join a small, high-calibre engineering team. This isn't a role for 'vibe coders'; you'll own features end-to-end, from Rust services to backend and frontend, with a mandate to ship high-quality code at speed using the latest AI tools. Expect deep technical problems, not just feature implementation. This role is 5 days a week in person in Hoxton, London.

The work

• Ship high-quality code at speed, leveraging the latest AI tools and models. This isn't optional.
• Own features end-to-end: from Rust services to backend logic and frontend implementation.
• Optimize for performance: eliminate allocations, tune queries, implement aggressive caching.
• Enhance our AI agent's intelligence by refining its harness, tools, and context optimization.
• Drive improvements across backend and infrastructure, from low-level bug fixes to CI optimization.

What You Bring

• Demonstrable track record as a top-tier engineer.
• Expertise in leveraging AI for coding, including advanced prompting and familiarity with various models (e.g., Claude Code, Cursor).
• Experience owning features end-to-end across the stack (Rust, TypeScript, React, backend, frontend).
• A deep understanding of performance optimization and infrastructure.
• Ability to work 5 days a week in our Hoxton, London office.

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