Founding Senior Backend Engineer

Founding Senior Backend Engineer Location: London, On-Site Package: Competitive Salary + Equity, Tokens and Benefits package.

The Company: Money should move at the speed of conversation. Not trapped behind forms and buttons, but flowing through voice and text as naturally as thought. From sending cash, to investing in the market, The Client is making money truly conversational. They believe the future of money is programmable, and the future of human-computer interaction is conversational and agentic. They are building the translation layer. Secure, reliable infrastructure that connects natural language to financial execution, and unlocks a new economy where every AI agent becomes a financial actor. Their founding engineering team has built core infrastructure at WorldCoin, the OP Stack, and the Ethereum Foundation. They understand what it takes to build global financial infrastructure that scales. They have proven this works with real users and now they are building the infrastructure to power every financial conversation.

About the Role As a Senior Founding Backend Engineer, you will take technical ownership of the backend architecture, infrastructure, and developer platform. This is a pivotal, high-impact role where your decisions influence the core product, the engineering culture, and the long-term system design for mission-critical financial applications.

Responsibilities

• Architect and build core backend infrastructure from the ground up with a security-first mindset
• Develop APIs, SDKs, and developer tools that make conversational finance seamless to integrate
• Create systems for API management, usage tracking, metering, and billing
• Build frameworks for integrating new blockchains, protocols, and financial networks
• Establish robust deployment processes and high-reliability operational flows
• Help mentor, and scale a world-class engineering team

Requirements

• 5+ years’ experience building and maintaining production backend systems at scale
• Proven track record shipping developer tools, APIs, or infrastructure products
• Strong proficiency in Typescript
• Deep understanding of modern API development, distributed systems, reliability, and scaling
• Security-first approach to designing financial or mission-critical systems
• Ability to produce clear, developer-friendly technical documentation

• Experience with Node.js, PostgreSQL, Redis, AWS/Terraform
• Background in payments, financial services, or crypto infrastructure
• Experience writing technical content or contributing to open source
• Exposure to LLMs and systems design for AI reliability

What We Offer

• Competitive salary
• Equity + token warrants
• Comprehensive UK benefits package (wellness stipend, L&D budget, food & tech)
• Private medical insurance
• Multiple team off sites per year
• Generous time-off policy

Location This is a London-based role. Open to candidates already in London or willing to relocate. (Uk Citizens, Visa Not supported at this time)

How to Apply Click Apply and Send your CV, links to previous work, or anything that shows how you think and build!