Founding Engineer, Agent Systems

Posted 5 hours 11 minutes ago by C&D Talent Advisory

Permanent
Full Time
Other
Hertfordshire, St. Albans, United Kingdom, AL1 1
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