AI Engineer at StackOne

Job Title

AI Engineer

Not Disclosed

Stack One is a $24M VC-funded AI Integration Gateway backed by GV and Workday Ventures. They provide builders of SaaS platforms and AI Agents with a unified toolkit to orchestrate hundreds of enterprise-grade integrations, combining a real-time architecture with 25,000 pre-mapped actions across 200 connectors.

As an AI Engineer at Stack One, you will build the future of agentic integrations by delivering end-to-end AI products. Reporting to the CTO, you'll work with AI researchers to develop specialized LLMs for tool-calling, ensuring precision and reliability in agentic execution while maintaining high-performance inference pipelines and retrieval systems.

London, UK

• Work at the frontier of AI R&D, building specialized LLMs designed for tool-calling and agentic execution rather than just general-purpose applications.
• Join a high-growth startup backed by elite investors like GV and Workday Ventures, scaling a platform that already powers thousands of integrations.
• Collaborate with a world-class veteran engineering team from industry leaders like Google, Microsoft, and Coinbase in a culture built on shipping and ownership.

• Design and deploy full-stack features including inference pipelines, embeddings, and retrieval systems across AWS and Cloudflare.
• Implement cutting-edge tool-calling and Model Context Protocol (MCP) patterns to enable one-click agent integrations with any tool.
• Develop and maintain high-quality open-source and internal Type Script and Python packages to accelerate the developer ecosystem.

• Professional experience shipping production-grade applications using Generative AI and LLMs like GPT or Anthropic.
• Expert proficiency in Type Script and Python with a proven track record of building scalable systems on AWS, GCP, or Cloudflare.
• Strong background in full-stack engineering with experience publishing SDKs, CLIs, or complex packages in a fast-paced environment.