Senior Python Software Engineer

Senior Python Software Engineer – AI Integrations

Industry: AI / Developer Platforms / Distributed Systems

Location: UK / Europe - Fully Remote

Salary: Competitive Base + Equity / Bonus Potential

X4 Engineering are working with a highly innovative, early-stage AI platform company that is building the connective tissue for the next generation of AI systems.

They are seeking a Senior Python Software Engineer to take ownership of their developer-facing integration layer. This role sits at the heart of the platform, responsible for building the SDKs that allow developers to connect AI agents into a multi-agent communication system in minutes rather than weeks.

In this role, you will design and evolve a production-grade Python SDK used by external developers, implementing adapters for leading agent frameworks, integrating directly with frontier model APIs, and shaping emerging agent-to-agent communication standards. You’ll focus heavily on API ergonomics, developer experience, and reliability, while working on genuinely bleeding-edge problems where protocols and best practices are still being defined.

Key Requirements

• 7+ years of professional Python experience with strong OOP fundamentals
• Deep experience with asyncio, type hints, and Pydantic
• Proven background building and maintaining SDKs, libraries, or developer tools used by external teams
• Familiarity with AI / LLM frameworks such as LangChain, LangGraph, Pydantic AI, AutoGen, or similar
• Strong API design instincts with a focus on usability and developer experience
• Experience designing and consuming REST and WebSocket APIs

Nice to Have

• Exposure to agent-to-agent protocols (A2A, MCP, ACP) or distributed messaging standards
• Multi-language experience (TypeScript, Go, Rust, Elixir)
• Contributions to open-source AI or developer tooling projects
• Startup or early-stage experience, comfortable operating with ambiguity and speed

If you’re interested in exploring this opportunity, please get in touch at or apply directly via the job advert.