Founding Engineer, Agent Systems

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

Benefits offered by this job

On-site London office

Roof terrace

Daily team lunch

Specialty coffee

Equity

Job summary

C&D Talent Advisory is seeking a Founding Engineer to join a seed-stage AI startup in London. Work on risk infrastructure for regulated enterprises and own the agent platform powering customer-facing AI features.

Based in London with on-site work, you will shape multi-step workflows, tool-calling systems, and reliability layers around frontier LLMs while operating with founding-team ownership and influence on engineering standards.

Qualifications

• Must have production-level backend experience and comfort owning end-to-end features.
• Experience shipping LLM-powered features in production environments.
• Strong TS/Node.js proficiency and familiarity with API design.
• Hands-on with agent frameworks and multi-step orchestration.
• Experience building AI evaluation pipelines and data curation.
• Understanding of AI reliability, failure modes, and prompt controls.

Responsibilities

• Build and evolve the core agent orchestration platform.
• Design multi-step agent workflows and tool-calling systems.
• Develop context-management and agent scaffolding infrastructure.
• Implement sandboxing and security controls for agent execution.
• Create production evaluation frameworks for high-stakes outputs.
• Own versioning and reliability for AI features.
• Define internal standards for production AI quality.
• Collaborate with founding team on architecture decisions.

Skills

Production LLM features

Backend engineering

TypeScript/Node.js

Agent frameworks

Tool calling & orchestration

AI evaluation

Dataset curation

Asynchronous systems

Reliability patterns

Product ownership

Tools

Anthropic API

OpenAI APIs

Claude Code

Agent orchestration frameworks

Job description

Founding Engineer, Agent Systems | London

• Location: King's Cross, London
• Work model: On-site by default, with some flexibility
• Employment: Full-time
• Level: Mid-Senior / Founding Engineer
• Experience: Typically 6–7+ years, with flexibility for exceptional AI-native profiles
• Estimated compensation: £130,000–£170,000 +Equity
• Industry: Enterprise AI / Agent Systems
• Environment: Seed-stage, high-growth startup

About the opportunity

• Join a seed-stage company building AI-native risk infrastructure for regulated enterprises
• Work on production AI systems used across financial services, regulated technology, and healthcare
• Own the agent platform powering customer-facing AI features
• Build the orchestration, evaluation, and reliability layers around frontier LLMs
• Turn model capabilities into production systems that domain experts can trust
• Set engineering standards for when AI features are reliable enough to ship
• Operate with founding-team levels of ownership and technical influence
• Work in a company already generating seven-figure revenue through multi-year enterprise contracts

What you'll own

• 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

What we're looking for

• Strong professional backend engineering experience
• 1–2+ years of experience 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
• Strong systems-thinking ability
• Experience with asynchronous systems and queues
• Understanding of idempotency and reliability patterns
• Strong product-engineering mindset
• Ability to own features from customer problem through production deployment
• High level of autonomy and accountability
• Based in London or able to commute regularly for an on-site-first role

Particularly valuable experience

• Anthropic APIs
• OpenAI APIs
• Open-weight models
• Production LLM workloads at scale
• Agent orchestration frameworks
• AI evaluation infrastructure
• Model fallback architecture
• Prompt versioning
• Prompt-injection defense
• Agent security
• Sandboxed tool execution
• Production RAG systems
• High-stakes AI applications
• Compliance
• Governance, Risk and Compliance (GRC)
• Audit technology
• Cybersecurity
• Financial services
• Regulated enterprise software

Strong profile signals

• Former founder or technical founder
• Former CTO returning to hands‑on engineering
• Founding or early‑stage engineering experience
• Experience at a high‑growth product company
• Experience at a leading technology or AI organization
• Significant independent AI projects or side projects
• Strong evidence of product ownership
• History of shipping customer‑facing systems end‑to‑end
• AI‑native development workflow
• Heavy use of coding agents such as Claude Code or equivalent
• Ability to move between product, backend, AI systems, and reliability work
• Strong technical judgment rather than purely research‑oriented expertise

This role may not be the right fit if you

• Have exclusively front‑end or front‑end‑first engineering experience
• Have a purely AI research background without production software engineering ownership
• Have worked primarily in Developer Relations or Developer Experience
• Have only built internal AI tools rather than customer‑facing production systems
• Lack meaningful backend engineering experience
• Have AI experience limited to prototypes or demos
• Prefer research over shipping production products
• Lack experience taking ownership of production reliability
• Prefer narrowly scoped engineering responsibilities
• Are uncomfortable making judgment calls around AI quality and production readiness
• Are not comfortable working primarily on‑site in London

Technical environment

• TypeScript
• Node.js
• React
• Tailwind
• Express
• Azure
• Postgres
• Terraform
• GitHub Actions
• Docker
• Anthropic‑first AI stack
• Claude Code

What you'll get

• Founding-level ownership of the agent platform
• Significant influence over AI architecture and engineering standards
• Opportunity to build production‑grade agent systems from an early stage
• Direct impact on customer‑facing AI quality and reliability
• Exposure to frontier LLM APIs in demanding production environments
• Work on technically difficult evaluation and reliability problems
• Close collaboration with company leadership
• Top‑decile London market compensation
• Meaningful EMI‑eligible equity
• Significant AI tooling and API budgets
• Daily team lunch
• Specialty coffee
• King's Cross office with roof terrace and on‑site facilities
• Fast-moving engineering environment with high autonomy