Senior AI Engineer in London

Boldspace is a 6-year-old full-service Brand & communications agency that has experienced year-over-year growth since its founding. Our seasoned agency-side co-founders felt there was a critical lack of industry transparency in data and measuring the performance of client work, so we launched BoldStream on day 1, our flagship data & analytics platform that helps brands measure and act on the impact of their communications in real time. We will now continue to invest heavily in AI-native capabilities: agentic workflows, retrieval-augmented insights, and intelligent automation across our client reporting and analytics stack.

We’re looking for a Senior AI Engineer to own end-to-end delivery of AI-powered features across BoldLoop and related internal products. You’ll sit at the intersection of OpenAI's latest agentic tooling, LangChain/LangGraph, TypeScript, and Supabase, building production-grade systems rather than prototypes. This role is hands-on and full-stack: from designing LLM-powered workflows and data models to shipping polished front-end experiences and observability for everything you release.

• AI & Agentic Product Development
  • Design and implement agentic workflows using OpenAI (Responses API, AgentKit & Agent Builder) and LangChain/LangGraph for use cases like analytics copilots, automated reporting, insight generation and internal tools.
  • Build and tune prompts, tools and orchestration logic to make agents reliable: handle tool-calling, multi-step reasoning, fallbacks, and guardrails.
  • Architect and implement RAG pipelines (embeddings, vector stores, retrieval strategies, caching) using Supabase and other data sources to ground models in BoldLoop and client data.
• Full-Stack Engineering
  • Backend: TypeScript/Node or edge functions, Supabase (Postgres + vector store), API design, schema design, migrations and performance tuning.
  • Frontend: Modern TypeScript front-ends (React / Next.js or similar) for analytics dashboards, workflows and internal tooling.
  • Integrate OpenAI and other LLM providers in a way that is robust, observable, and cost-aware (tracing, token usage monitoring, rate limiting, retries).
  • Work closely with data engineers / analysts to expose BoldLoop metrics, models and datasets through AI features that feel intuitive to non-technical users.
• Engineering Quality & Platform Foundations
  • Champion testing, observability and reliability for AI features: unit tests, integration tests, synthetic evals for prompts, and health checks for agent workflows.
  • Contribute to and improve CI/CD pipelines, deployment strategies and cloud infrastructure supporting AI workloads.
  • Use GitHub, Linear and AI-enhanced tooling (Cursor, Lovable, etc.) to move quickly while maintaining high standards.
• Collaboration & Leadership
  • Translate business and product requirements into technical designs and implementation plans for AI features.
  • Provide technical leadership within the AI / BoldLoop squad, mentoring engineers on LLM patterns, agentic architectures and best practices.
  • Partner with Product, Data, Client Services and Strategy to define AI roadmaps that unlock measurable value for clients.

Skills & Experience

• 5+ years experience as a Full-Stack / Backend Engineer, with at least 2+ years building LLM-powered products in production.
• Strong TypeScript and JavaScript fundamentals; production experience with Node.js backends and modern front-end frameworks.
• Hands-on experience with LangChain and/or LangGraph, ideally including multi-agent or complex tool-using workflows.
• Proven experience integrating OpenAI APIs (chat, Responses, Agents SDK) into production systems.
• Solid experience with Supabase or similar (Postgres, auth, edge functions, vector search) and data modelling for analytics and content.
• Deep understanding of RAG, prompt engineering, evaluation, and safety/guardrail patterns for LLM applications.
• Comfortable with CI/CD, cloud infrastructure and observability for distributed systems.

Nice to have

• Experience with additional AI frameworks (CrewAI, LangFlow, semantic search stacks, etc.).
• Exposure to analytics or martech platforms, especially where data storytelling and communication impact are key.
• Experience with AI-assisted developer tools (Cursor, Lovable) and low-code platforms where appropriate.

What You'll Bring

• Engineering rigour – a track record of shipping reliable systems, instrumenting them well, and improving them over time.
• AI product mindset – you think in terms of user journeys, failure modes and measurable impact, not just model calls.
• Systems thinking – you understand how agents, tools, data and UI fit together to deliver value end-to-end.
• Collaboration – clear communication, especially when explaining AI systems to non-technical stakeholders.

Benefits

• Pensions: a 5% employer contribution.
• Private Healthcare: Vitality.
• Holiday: unlimited holiday (including all UK public holidays) – we trust our staff to take the time they need and still excel in their jobs – and days off for birthdays and moving house is guaranteed!
• Very Flexible working.
• Socials: team socials regularly, chosen by the team.
• Team retreats: time to get to know each other away from the office.
• Bonus: transparent bonus structure where you can receive a % of base salary based on personal and company performance.
• Supporting good causes: we contribute some of our outperformance to charitable causes which the team help choose.
• Wellness: time within working hours every week for those that want or need it.
• Monthly benefits budget: £50 per month, every month, to spend on whatever you want – from a home delivered vegetable box and discounted gym memberships, to mental health support and professional coaching.
• A CARBON NEUTRAL BUSINESS: Boldspace measures its performance on profit, people and planet combined. From day one, we will offset your carbon footprint entirely. The cost of this is covered 100% by the company.