Founding Product Engineer at Briefcase

Join a high-performance team in London building a fleet of 15+ AI agents that automate complex financial workflows. As a founding engineer, you will ship code 20-30 times daily, architecting core features across React, TypeScript, and Temporal to redefine the industry’s system of record from the ground up.

• Build and deploy industry-leading AI agents that handle end-to-end accounting workflows with humans-in-the-loop only where necessary.
• Engage directly with customers to identify pain points and rapidly iterate on product features from first principles.
• Drive technical decisions across the entire stack, refining architecture choices and experimenting with new tools to maintain high shipping velocity.

• Proven track record of outperforming peers in high-growth environments with a deep passion for modern AI and product design.
• Expert-level proficiency in React, TypeScript, and GraphQL, with an interest in working with Temporal and AWS infrastructure.
• Strong bias for action and in-person collaboration, thriving in a fast-paced London-based office where the team ships dozens of times per day.

• Radical Agency: You will own the product roadmap end-to-end, moving from customer discovery to production deployment with total autonomy in a high-urgency environment.
• Frontier Tech: Work at the bleeding edge of AI agents, leveraging a modern stack including Langsmith, GraphQL, and bespoke data platforms to replace manual accounting.
• Founding Impact: As an early hire, you will directly shape the technical architecture, company culture, and product vision alongside a team of top-tier ambitious engineers.