Founding AI Engineer, Agent Platform (Equity)

Cross Border Talents; Welwyn Garden City; On-site; GBP 130,000 - 170,000; Full time

Benefits offered by this job

Equity

Job summary

Cross Border Talents is hiring a Founding Engineer for Agent Systems in London. The role is on-site with some flexibility, full-time, mid-senior level, and includes equity. You will own the agent platform, orchestration, evaluation, and reliability around frontier LLMs for regulated enterprise environments.

We seek a strong backend engineer with 6–7+ years of experience, capable of shipping production AI features and owning production-quality systems end-to-end.

Qualifications

• Strong backend engineering experience.
• 6–7+ years in relevant roles with flexibility for exceptional profiles.
• Experience shipping production LLM-powered features (1–2+ years).
• Proficiency in TypeScript or Node.js.
• Hands-on with agent frameworks and tool calling.
• Experience building AI evaluation and regression testing.
• Ability to own features end-to-end from problem to production.

Responsibilities

• Build and evolve the core agent orchestration platform.
• Design multi-step agent workflows and tool-calling systems.
• Develop secure sandboxing for agent execution and reliability layers.
• Implement prompt-injection defenses and AI-security controls.
• Create production evaluation frameworks for high-stakes outputs.
• Own versioning, queues, and idempotent processing for AI workloads.

Skills

Backend engineering

LLM features

TypeScript/Node.js

Agent systems

Asynchronous systems

Reliability

Product ownership

Security

Dataset curation

Evaluation frameworks

Tools

TypeScript

Node.js

React

Terraform

Docker

Postgres

Azure

GitHub Actions

Claude/Athropic stack

Job description

Cross Border Talents is hiring a Founding Engineer for Agent Systems in London. The role is on-site with some flexibility, full-time, mid-senior level, and includes equity. You will own the agent platform, orchestration, evaluation, and reliability around frontier LLMs for regulated enterprise environments.

We seek a strong backend engineer with 6–7+ years of experience, capable of shipping production AI features and owning production-quality systems end-to-end.