Founding Engineer, AI Agent Systems - London, Equity

C&D Talent Advisory; Cambridge; On-site; GBP 130,000 - 170,000; Full time

Benefits offered by this job

Roof terrace

On-site facilities

EMI-eligible equity

Daily team lunch

Specialty coffee

Job summary

TechTree is recruiting for a Founding Engineer, Agent Systems in London (King's Cross). This on-site, full-time role offers founding-level ownership of the agent platform and the chance to shape AI reliability for high-stakes production systems.

You'll own orchestration, multi-step workflows, sandboxing, and AI-quality infrastructure, building production-grade agent systems in a seed-stage, high-growth startup with seven-figure revenue from enterprise contracts.

Qualifications

• Strong professional backend engineering experience.
• 1–2+ years shipping production LLM-powered features.
• Strong TypeScript or Node.js experience.
• Experience building customer-facing production AI systems.
• Hands-on experience with agent frameworks.
• Experience with tool calling and multi-step orchestration.
• Production experience building AI evaluations.
• Experience with dataset curation and regression testing.
• Understanding of LLM-as-judge approaches and failure modes.

Responsibilities

• Build and evolve the core agent orchestration platform.
• Design multi-step agent workflows and tool-calling systems.
• Build context-management and agent-scaffolding infrastructure.
• Develop secure sandboxing for agent execution.
• Implement prompt-injection defenses and other agent-security controls.
• Build production evaluation frameworks for fuzzy, high-stakes outputs.
• Curate evaluation datasets and regression suites.
• Design and improve LLM-as-judge systems.
• Evaluate model performance across upgrades and provider changes.
• Build retries, fallbacks, and circuit-breaker mechanisms.
• Own prompt versioning and AI-quality infrastructure.
• Design systems around async processing, queues, and idempotency.
• Define the internal standard for production AI quality.
• Own AI reliability and make ship/no-ship decisions when necessary.

Skills

Backend engineering

LLM features

TypeScript

Node.js

Agent frameworks

Tool calling

AI evaluations

Asynchronous systems

Systems thinking

Ownership

Tools

Docker

Postgres

Terraform

GitHub Actions

Azure

Express

Claude Code

Job description

TechTree is recruiting for a Founding Engineer, Agent Systems in London (King's Cross). This on-site, full-time role offers founding-level ownership of the agent platform and the chance to shape AI reliability for high-stakes production systems.

You'll own orchestration, multi-step workflows, sandboxing, and AI-quality infrastructure, building production-grade agent systems in a seed-stage, high-growth startup with seven-figure revenue from enterprise contracts.